# data[].attributes.headline
Biosphere: All living things and all the places they are found Earth.Biodiversity: Variety of life.Species: Particular type of living things that can reproduce by interbreeding among themselves.Biology: The scientific study of all forms of life, or all types of organisms.Organism: Any individual living thing.Cell: The basic unit of  life.Metabolism: All of the chemical process that build up or break down materials.DNA: Deoxyribonucleic acid.System:  Organized group of related parts that interact to form a whole.Ecosystem: Physical environment with different species interact with another and with nonliving things.Homeostasis: maintenance of constant internal conditions in a organism.  Evolution: the change of living things over time.Adaptation:  inherited traits passed of future generations.Observation: using your senses to study the world.Data: can be analyzed.Hypothesis: a proposed answer to a scientific question.Experiment: tests that test a hypothesis.Independent variable: condition that are changed or manipulated. Dependent variable: depends on the independent or manipulated thing Constant: the conditions that does not change in a experiment. Theory: proposed explanation for a wide range of observations and experimental results that is supported by a wide range of evidence.Microscope: provides a enlarged image of a object.Gene: segment of a dna.Molecular genetics: study and manipulation of dna. Genomics: the study of and comparison of genomes both within and across species.Genomics: biotechnology: the use and application of living things and biological process. Transgenic: organisms that have genes from more than one species, or have altered copies of their own gene

# data[].attributes.subject
Biosphere: All living things and all the places they are found Earth.Biodiversity: Variety of life.Species: Particular type of living things that can reproduce by interbreeding among themselves.Biology: The scientific study of all forms of life, or all types of organisms.Organism: Any individual living thing.Cell: The basic unit of  life.Metabolism: All of the chemical process that build up or break down materials.DNA: Deoxyribonucleic acid.System:  Organized group of related parts that interact to form a whole.Ecosystem: Physical environment with different species interact with another and with nonliving things.Homeostasis: maintenance of constant internal conditions in a organism.  Evolution: the change of living things over time.Adaptation:  inherited traits passed of future generations.Observation: using your senses to study the world.Data: can be analyzed.Hypothesis: a proposed answer to a scientific question.Experiment: tests that test a hypothesis.Independent variable: condition that are changed or manipulated. Dependent variable: depends on the independent or manipulated thing Constant: the conditions that does not change in a experiment. Theory: proposed explanation for a wide range of observations and experimental results that is supported by a wide range of evidence.Microscope: provides a enlarged image of a object.Gene: segment of a dna.Molecular genetics: study and manipulation of dna. Genomics: the study of and comparison of genomes both within and across species.Genomics: biotechnology: the use and application of living things and biological process. Transgenic: organisms that have genes from more than one species, or have altered copies of their own gene

# data[].attributes.headline
Science as process: The word science is derived from a Latin verb meaning "to know." That is, biology is an ongoing process of learning, not just a list of facts.Evolution: Evolution is simply how living things evolve, or change, over time. It explains inherited similarities in organisms and causes of variation.Energy transfer: All organisms perform work as they move, grow, and reproduce and need an energy source to do so. Organisms constantly transfer energy to their surroundings, and vice versa. This transfer involves the conversion of one form of energy into another.Continuity and change: Organisms reproduce to ensure their species continues. But combining genes also results in variations in offspring.Relationship of structure to function: Every type of organism has developed parts to adapt to its habitat. Birds have different kinds of beaks, and plants have different kinds of seeds, for example.Regulation: Also called homeostasis. Cells, animals, and ecosystems work to maintain stable internal conditions, such as body temperature, even when external conditions change.Interdependence in nature: The flow of energy and cycling of matter are the two processes that determine the relationships between organisms and their surroundings.Science, technology, and society: Scientific inquiry should consider the ethical and social impact of the research. In other words, scientists must make decisions based on what society should do over what it can do.Newer Research MethodsAs scientists learned more about nature and science, they began to challenge established ideas like spontaneous generation.This was the beginning of what is now known as scientific inquiry. Scientists use three key methods to research and analyze data: observation, investigation, and experimentation. Scientific inquiry begins with observation. It is a process in which scientists gather information in an orderly manner. They record their observations, which become data that they categorize. Data is of two types: Numerical data is called quantitative data.Descriptive data, data that cannot be counted, is called qualitative data. An example of quantitative data is, "A plant has 10 leaves." An example of qualitative data is, "The leaves are healthy."Based on the data she's gathered, a scientist may propose a hypothesis. A hypothesis is a question framed by a scientist to explain a set of observations. It's a prediction that must be testable. So the scientist must conduct experiments or do more investigation.A hypothesis isn't always proven correct. Experiments or investigation may prove the hypothesis wrong. Then the scientist must reformulate the hypothesis and start over again.Common Metric UnitsLength1 meter = 100 centimeters1000 meters = 1 kilometerMass1 kilogram = 1000 gramsVolume1 liter = 1000 millilitersTemperature0°C = freezing point of water100°C = boiling point of waterBiology, the study of life, is the science on which many kinds of study are based: medicine, nutrition, molecules, ecosystems, and more. Several themes, such as evolution and energy transfer, are consistent throughout Biology's many disciplines.Research methodologies have undergone a significant change over the years. Observation, investigation, and experimentation remain the backbone of research, but microscopes and computers have greatly enhanced scientific knowledge and study.The data gathered by researchers must be organized and analyzed so that it is useful. Tables and graphs are good ways to represent data.Explore some exciting careers in biology and its interdisciplinary branches. Perhaps you'll find the career you're meant for!Everything in our enormous universe is either matter or energy. Matter defines the physical objects; energy drives them to perform work. The study of matter and how it reacts is chemistry. The study of energy is physics.Biology incorporates both. This lesson is about some basic chemistry because when you know that, you will understand biology better.Covalent bonds are generally stronger than ionic bonds. Also, covalent bonds form when neutral atoms share electrons, instead of ions. How atoms share electrons depends on how the electrons in different atomic orbitals are distributed.Most atoms have more than one orbital around their nucleus. As the atomic number of an atom increases, the number of orbitals also increases. The outermost orbital, called the valence shell, is the one that forms the bond. Atoms bind to one another so that the valence shell of each atom has eight electrons. Again, let's use the element carbon to explain.The carbon atom contains six electrons and has two orbitals: two electrons in the one closer to the nucleus and four in the outer one. So the carbon atom seeks other atoms with four electrons in their valence shells to share so that each atom has eight electrons. Look at the picture to see how carbon and oxygen share electrons to form carbon dioxide.In organisms, compounds rarely exist as pure substances. They typically form mixtures with other compounds. There are three types of mixtures:solutions, suspensions, and colloids. Mixtures can be of any two or more chemical compounds, but in biology, we mostly study mixtures of water with other compounds. (Remember, all living things are mostly water.)When water mixes with a compound, it forms an aqueous solution.Aqueous solutions differ in density of concentration measured by molarity. Molarity is the number of moles of a chemical compound dissolved per liter of water. In other words, the higher the molarity, the higher the concentration.You can see the difference between solutions and suspensions in a simple experiment. Add a spoonful of salt to a glass of water. Stir until you don't see the salt anymore. In another glass of water add some soil.No matter how long you stir this mixture, the soil won't dissolve.So that's one difference: a solution is a mixture in which a solute (in this case, salt) dissolves in a solvent (in this case, water). Also, the solution is clear. Substances like salt and sugar homogenize completely in water so that you can't see any solid particles.The water to which you added soil is cloudy. It's called a suspension because the soil particles are suspended in the water. They can sediment, or settle to the bottom, if left undisturbed. Also, in a suspension, it's possible to separate the particles from the liquid because they're big.It's important to know a little chemistry in order to understand biological systems because all living things are composed of chemical compounds of some sort. An atom is the basic unit of matter, consisting of three main parts: protons, neutrons, and electrons. Protons have a positive charge, and electrons have a negative charge. Neutrons are neutral.Atoms of the same type combine to form an element. All atoms of the same element have the same number of protons, which give it its atomic number. Elements arranged in order of their atomic numbers from smallest to largest form the periodic table.Atoms of the same element with different numbers of neutrons are called isotopes. Isotopes have many uses in medicine, food preservation, and other professions.Atoms with fewer or more electrons than protons are called ions.Positive ions can combine with negative ones to form ionic bonds, which are weak. Conversely, covalent bonds are strong. They are formed when neutral atoms share electrons.

# data[].attributes.subject
Science as process: The word science is derived from a Latin verb meaning "to know." That is, biology is an ongoing process of learning, not just a list of facts.Evolution: Evolution is simply how living things evolve, or change, over time. It explains inherited similarities in organisms and causes of variation.Energy transfer: All organisms perform work as they move, grow, and reproduce and need an energy source to do so. Organisms constantly transfer energy to their surroundings, and vice versa. This transfer involves the conversion of one form of energy into another.Continuity and change: Organisms reproduce to ensure their species continues. But combining genes also results in variations in offspring.Relationship of structure to function: Every type of organism has developed parts to adapt to its habitat. Birds have different kinds of beaks, and plants have different kinds of seeds, for example.Regulation: Also called homeostasis. Cells, animals, and ecosystems work to maintain stable internal conditions, such as body temperature, even when external conditions change.Interdependence in nature: The flow of energy and cycling of matter are the two processes that determine the relationships between organisms and their surroundings.Science, technology, and society: Scientific inquiry should consider the ethical and social impact of the research. In other words, scientists must make decisions based on what society should do over what it can do.Newer Research MethodsAs scientists learned more about nature and science, they began to challenge established ideas like spontaneous generation.This was the beginning of what is now known as scientific inquiry. Scientists use three key methods to research and analyze data: observation, investigation, and experimentation. Scientific inquiry begins with observation. It is a process in which scientists gather information in an orderly manner. They record their observations, which become data that they categorize. Data is of two types: Numerical data is called quantitative data.Descriptive data, data that cannot be counted, is called qualitative data. An example of quantitative data is, "A plant has 10 leaves." An example of qualitative data is, "The leaves are healthy."Based on the data she's gathered, a scientist may propose a hypothesis. A hypothesis is a question framed by a scientist to explain a set of observations. It's a prediction that must be testable. So the scientist must conduct experiments or do more investigation.A hypothesis isn't always proven correct. Experiments or investigation may prove the hypothesis wrong. Then the scientist must reformulate the hypothesis and start over again.Common Metric UnitsLength1 meter = 100 centimeters1000 meters = 1 kilometerMass1 kilogram = 1000 gramsVolume1 liter = 1000 millilitersTemperature0°C = freezing point of water100°C = boiling point of waterBiology, the study of life, is the science on which many kinds of study are based: medicine, nutrition, molecules, ecosystems, and more. Several themes, such as evolution and energy transfer, are consistent throughout Biology's many disciplines.Research methodologies have undergone a significant change over the years. Observation, investigation, and experimentation remain the backbone of research, but microscopes and computers have greatly enhanced scientific knowledge and study.The data gathered by researchers must be organized and analyzed so that it is useful. Tables and graphs are good ways to represent data.Explore some exciting careers in biology and its interdisciplinary branches. Perhaps you'll find the career you're meant for!Everything in our enormous universe is either matter or energy. Matter defines the physical objects; energy drives them to perform work. The study of matter and how it reacts is chemistry. The study of energy is physics.Biology incorporates both. This lesson is about some basic chemistry because when you know that, you will understand biology better.Covalent bonds are generally stronger than ionic bonds. Also, covalent bonds form when neutral atoms share electrons, instead of ions. How atoms share electrons depends on how the electrons in different atomic orbitals are distributed.Most atoms have more than one orbital around their nucleus. As the atomic number of an atom increases, the number of orbitals also increases. The outermost orbital, called the valence shell, is the one that forms the bond. Atoms bind to one another so that the valence shell of each atom has eight electrons. Again, let's use the element carbon to explain.The carbon atom contains six electrons and has two orbitals: two electrons in the one closer to the nucleus and four in the outer one. So the carbon atom seeks other atoms with four electrons in their valence shells to share so that each atom has eight electrons. Look at the picture to see how carbon and oxygen share electrons to form carbon dioxide.In organisms, compounds rarely exist as pure substances. They typically form mixtures with other compounds. There are three types of mixtures:solutions, suspensions, and colloids. Mixtures can be of any two or more chemical compounds, but in biology, we mostly study mixtures of water with other compounds. (Remember, all living things are mostly water.)When water mixes with a compound, it forms an aqueous solution.Aqueous solutions differ in density of concentration measured by molarity. Molarity is the number of moles of a chemical compound dissolved per liter of water. In other words, the higher the molarity, the higher the concentration.You can see the difference between solutions and suspensions in a simple experiment. Add a spoonful of salt to a glass of water. Stir until you don't see the salt anymore. In another glass of water add some soil.No matter how long you stir this mixture, the soil won't dissolve.So that's one difference: a solution is a mixture in which a solute (in this case, salt) dissolves in a solvent (in this case, water). Also, the solution is clear. Substances like salt and sugar homogenize completely in water so that you can't see any solid particles.The water to which you added soil is cloudy. It's called a suspension because the soil particles are suspended in the water. They can sediment, or settle to the bottom, if left undisturbed. Also, in a suspension, it's possible to separate the particles from the liquid because they're big.It's important to know a little chemistry in order to understand biological systems because all living things are composed of chemical compounds of some sort. An atom is the basic unit of matter, consisting of three main parts: protons, neutrons, and electrons. Protons have a positive charge, and electrons have a negative charge. Neutrons are neutral.Atoms of the same type combine to form an element. All atoms of the same element have the same number of protons, which give it its atomic number. Elements arranged in order of their atomic numbers from smallest to largest form the periodic table.Atoms of the same element with different numbers of neutrons are called isotopes. Isotopes have many uses in medicine, food preservation, and other professions.Atoms with fewer or more electrons than protons are called ions.Positive ions can combine with negative ones to form ionic bonds, which are weak. Conversely, covalent bonds are strong. They are formed when neutral atoms share electrons.

# data[].attributes.body
Tonicity

There​ ​are​ ​two​ ​types​ ​of​ ​transport​ ​for​ ​proteins​ ​and​ ​other​ ​substances​ ​in​ ​a​ ​cell.​ ​There​ ​is

active​ ​transport,​ ​and​ ​passive​ ​transport.​ ​Active​ ​transport​ ​requires​ ​chemical​ ​energy​ ​from​ ​the​ ​cell

to​ ​retrieve​ ​the​ ​molecules​ ​that​ ​it​ ​needs.​ ​Passive​ ​transport,​ ​on​ ​the​ ​other​ ​hand,​ ​requires​ ​no​ ​energy

from​ ​the​ ​cell.​ ​Molecules​ ​can​ ​move​ ​across​ ​the​ ​cell​ ​membrane​ ​using​ ​passive​ ​transport.​ ​It​ ​is​ ​know

to​ ​move​ ​from​ ​high​ ​to​ ​low​ ​concentration.​ ​There​ ​are​ ​two​ ​types​ ​of​ ​passive​ ​transport.​ ​The​ ​first​ ​is

Diffusion,​ ​and​ ​the​ ​second​ ​is​ ​Osmosis.​ ​There​ ​are​ ​three​ ​types​ ​of​ ​solutions​ ​that​ ​are​ ​the​ ​cause​ ​of

passive​ ​transport.​ ​These​ ​include;​ ​Isotonic,​ ​Hypotonic,​ ​and​ ​Hypertonic.​ ​Now,​ ​we​ ​shall​ ​walk

through​ ​an​ ​experiment​ ​that​ ​describes​ ​what​ ​each​ ​solution​ ​is,​ ​and​ ​the​ ​results,​ ​or​ ​outcomes​ ​of​ ​the

solution.

Suppose​ ​we​ ​have​ ​a​ ​beaker​ ​of​ ​water.​ ​The​ ​water​ ​has​ ​a​ ​.7mm​ ​of​ ​sugar.​ ​Then,​ ​we​ ​place​ ​in

a​ ​single​ ​cell,​ ​which​ ​also​ ​has​ ​.7mm​ ​of​ ​sugar.​ ​The​ ​concentration​ ​of​ ​both​ ​the​ ​solute​ ​and​ ​the​ ​solvent

are​ ​equal.​ ​Therefore,​ ​we​ ​are​ ​lead​ ​to​ ​believe​ ​that​ ​the​ ​solution,​ ​is​ ​isotonic.​ ​The​ ​amount​ ​of​ ​water

flowing​ ​into​ ​the​ ​cell,​ ​directly​ ​matches​ ​the​ ​amount​ ​of​ ​water​ ​flowing​ ​out​ ​of​ ​the​ ​cell.​ ​The​ ​cell​ ​then

remains​ ​the​ ​same,​ ​perfectly​ ​shaped.​ ​It​ ​does​ ​not​ ​swell,​ ​now​ ​does​ ​it​ ​shrivel.

In​ ​the​ ​next​ ​beaker,​ ​we​ ​have​ ​another​ ​single​ ​cell.​ ​The​ ​water​ ​has​ ​3.2mm​ ​of​ ​sugar,​ ​and​ ​the

cell​ ​has​ ​2.2mm​ ​of​ ​sugar.​ ​The​ ​balance​ ​between​ ​the​ ​solute​ ​and​ ​solvent​ ​have​ ​been​ ​altered.​ ​The

solution​ ​is​ ​now​ ​called,​ ​hypertonic.​ ​The​ ​water​ ​flowing​ ​into​ ​the​ ​cell,​ ​is​ ​much​ ​much​ ​less​ ​than​ ​the

amount​ ​of​ ​water​ ​flowing​ ​out​ ​of​ ​the​ ​cell.​ ​Therefore,​ ​the​ ​cell​ ​begins​ ​to​ ​shrivel​ ​up​ ​because​ ​it​ ​loses

the​ ​liquid​ ​inside​ ​of​ ​it.

In​ ​our​ ​last​ ​beaker,​ ​we​ ​have​ ​yet​ ​another​ ​single​ ​cell.​ ​The​ ​water​ ​on​ ​the​ ​outside​ ​of​ ​the​ ​cell​ ​is

2.2mm​ ​of​ ​sugar,​ ​and​ ​on​ ​the​ ​inside​ ​of​ ​the​ ​cell,​ ​it​ ​has​ ​3.3mm​ ​of​ ​sugar.​ ​The​ ​balance​ ​between​ ​the

water​ ​outside​ ​and​ ​inside​ ​of​ ​the​ ​cell​ ​is​ ​yet​ ​again,​ ​unbalanced.​ ​The​ ​water​ ​flowing​ ​into​ ​the​ ​cell,

moves​ ​at​ ​a​ ​greater​ ​speed​ ​than​ ​the​ ​water​ ​does​ ​moving​ ​out​ ​of​ ​it.​ ​Therefore,​ ​the​ ​cell​ ​begins​ ​to

swell.​ ​The​ ​more​ ​that​ ​the​ ​cell​ ​swells,​ ​the​ ​higher​ ​the​ ​possibility​ ​of​ ​it​ ​exploding.

# data[].attributes.body
An atom is the smallest basic unit of life.

An element is the one of atom.

Proton, neutron, electrons, three parts of a atom.

Nucleus is made up of protons and neutrons.

Atomic number = number of protons.

Atomic number can be found on the periodic table.

Number of protons=electron if it is neutral.

Mass number - atomic number = neutron.

Positive ion = cation    negative = anion.

Ionic bonds form between oppositely charged ions usually between metals and nonmetals.

Ionic bonds are the full transfer of electrons between metals and nonmetals.

A covalent bonds form when atoms share a pair of electrons. Happens between two nonmetals.

A solution is formed when one substance dissolves in another.

Solvents dissolves another substance .

Solute is dissolved.

Salt is a nacl.

The ph scales ranks from 0-14 middle number is 7  acidic high h+ concentration

7-above low h+ concentration more basic.

Neutrals are around 7.

Monomer is one thing many mers is  a polymer.

4 types of macromolecules

1:Carbohydrates=sugars   C-O-H

Monosaccharides are simple sugars

Polysaccharides are starches,cellulose and glycogen.

2: lipids are fats.

C-H-o

Are nonpolar. Are the polymer and monomer is the fatty acids

They are hydrophobic. - [water fearing]

[Water loving] -hydrophilic.

Saturated is solid unsaturated is liquid .

Phosphate are the head the tails or lipid or nonpolar.

Proteins are polymers of amino acid monomers.

Another name for protein is polypeptide.

Incorrect amino acids change  proteins structure and function.

Nucleic acids are the polymer of monomers called nucleotides.

Cellular energy is know as

[  ----- ]

[                 ]

[         ATP.     ]

[                  ]

[ -----]

Bonds break and form during chemical reactions.

Bond energy is the amount of energy that breaks the bond.

Activation energy is the amount of energy that needs to be absorbed to start reaction.

Exothermic reaction released.

Endothermic absorbs more energy that released.

“This week I want our focus to be on using our class time most efficiently. Often times we use class time to visit and not work on HW, ask questions, or study. Let's start this week by changing our habits and make it more of a natural thing to do during our free class time. ASK questions! WANT to learn! BE INVOLVED!”

Catalyst are use for speeding up a reaction by lowering the activation energy.

Enzymes are protein catalysts that speed up chemical reactions by lowering activation energy.

All enzymes end of- ase

Lock and key.

# data[].attributes.body
Ls.3 Atoms, Ions, and Molecules

- Living things consist of atoms of different elements.

An atom is the smallest basic unit of matter

> An element is one type of atom.

- An atom has a nucleus and electrons.

> The nucleus has protons and neutrons.

> Electrons are in energy levels outside nucleus.

Atomic # = # Protons

# Protons = # Electrons

Mass # - Atomic # = # Neutrons

Nucleus: 8 protons (+) 8 neutrons

-  A compound is made of atoms of different elements bonded together

- Ions form when atoms gain or lose electrons.

> An ion is an atom that has gained or lost one or more electrons.

* positive ions

* negative ions

Positive ions - cat ion

Negative ions - onion

> Ions bond form between oppositely charged ions.

* metal and nonmetals

* full transfer between metal and nonmetal

- Atoms share pairs of electrons in covalent bonds.

> A covalent bond forms when atoms share a pair of electrons.

* multiple covalent bonds

* diatomic molecules

Ls.3.2 Properties of Water

- Life depends on hydrogen bonds in water.

> Water is a polar molecules.

* Polar molecules have slightly charged regions.

* Nonpolar molecules do not have charged regions.

* Hydrogen bonds form between slightly positive, hydrogen atoms and slightly negative atoms.

> Hydrogen bonds are responsible for three important properties of water.

* high specific heat

* cohesion

* adhesion

Ls.3.2

Many compounds dissolve water.

A solution is formed when one substance dissolves in another

A solution is a homogen mixture

Solvent dissolves other substances

Solvent dissolves in solution

Like dissolves like

Polar solvents dissolve polar solutes.

Nonpolar Solvents dissolve nonpolar solutes.

Polar substance and nonpolar generally remain the same.

An acid releases a hydrogen ion when it dissolves in water .

A base removes hydrogen ions from a solution.

Ls.3.3

4 types of macromolecules (carbon based molecules)

1. Carbohydrates - sugar (COH)

2. Lipids - fats(CH little of oxygen)

- Four main types of carbon-based molecules are found in living things.

> Carbohydrates are made of carbon, hydrogen, and oxygen.

* Carbohydrates include sugars and starches.

* Monosaccharides are simple sugars.

* Polysaccharides includes starches, cellulose, and glycogen.

> Carbohydrates can be broken down to provide energy for cells.

> Some carbohydrates are part of cell structure.

> Lipids are nonpolar molecules that include fats, oils, and cholesterol.

* Many contain carbon chains called fatty acids.

* Fats and oils contain fatty acids bonded to glycerol.

* Water fearing - hydrophobic

* Water “loving” - hydrophilic

>  Lipids have several different functions.

* broken down as a source of energy

*

> Fats and oils have different types of fatty acids.

* Saturated fatty acids

* Unsaturated fatty acids

(Saturated fats contains fatty acids in which all carbon-carbon bonds are single bonds.)

(Unsaturated fats have fatty acids with at least one carbon-carbon double bond.)

> Phospholipids makeup all cell membranes.

* Polar

> Proteins are polymers of amino acid monomers.

* Twenty different amino acids are used to build proteins in organisms

* Amino acids differ in side groups, or R groups.

> Proteins differ in the number and order of amino acids.

* Amino acids interact to give a protein its shape.

* Incorrect amino acids changes a protein’s structure and function.

> Nucleic acids are polymers of monomers called nucleotides.

* Nucleotides are made of a sugar, phosphate group, and a nitrogen base.

* Cellular energy is known of ATP.

* DNA stores genetic information.

* RNA builds proteins.

Ls.3.4 Chemical Reactions

- Bonds break and form during chemical reactions

> Chemical reactions change substances into different ones by breaking and forming a chemical bond.

* Reactants are changed during a chemical reaction.

* Products are made by a chemical reaction.

>Bond energy is the amount of energy that breaks a bond.

* Energy is added to break bonds.

* Energy is released when bonds form.

>A reactions is at equilibrium when reactants and products form at the same rate.

CO2+H2O-H2CO3

- Chemical reactions release or absorb energy.

> Activation energy is the amount of energy that needs to be absorbed to start a chemical reaction.

> Exothermic reactions release more energy than they absorb.

* Reactants have higher bond energies than products.

* Excess energy is released by the reaction.

> Endothermic reactions absorb more energy than they release.

* Reactants have lower bond energies than products.

* Energy is absorbed by the reaction to make up the difference.

L.s3.5 Enzymes

Key Concept

Enzymes are catalysts for chemical reactions in living things.

- A catalyst lowers activation energy.

> Catalysts are substances that speed up chemical reactions.

* Decrease activation energy

* Increase reaction rate

* Enzymes are protein catalysts that speed up chemical reactions by lowering the activation energy

- Enzymes allow chemical reactions to occur under tightly controlled condition.

> Enzymes are catalysts in living things.

* Enzymes are needed for almost all processes.

* Most enzymes are proteins.

* All enzymes end in -ASE

> Disruptions in homeostasis can prevent enzymes from functioning.

* Enzymes function best in a small range of conditions.

* Changes in temp. and pH can break hydrogen bonds.

* An enzyme's function depends on its structure.

> The lock-and-key model helps illustrate how enzymes function.

* Substrates brought together

* Bonds in substrates weakened

* Substrates bind to an enzyme at certain places called active sites.

* The enzymes brings substrates together and weakens their bonds.

* The catalyzed reaction forms a product that is released from the enzyme.