Adhesion is water sticking to surfaces and other substances.

Since water is made up of hydrogen and oxygen, the covalent bonds allow for a structure in which the hydrogen can bond with other oxygen molecules. These bonds are weak and are called hydrogen bonds.

Water will dissolve polar and ionic substances as it weakens intermolecular forces and disassociates the atoms. All substances that dissolve in water are called hydrophilic. 

Enzymes and their substrates meet due to the result of random collisions between molecules. When the temperature will be low, the velocity of the molecules is very low therefore the likelihood of collisions is decreased. This will slow down the production of products. As the temperature rises, the collisions will become more frequent due to higher kinetic energy. At a certain point, the optimum temperature will be reached. This is when the most collisions are occurring due to high kinetic energy. If it becomes too hot, the enzyme will denature, causing less reactions.

 

Enzyme action is influenced by pH because the amino acids that make up an enzyme molecule contain many positive and negative regions, some of which are around the active site. Enzymes work best at the optimum temperature where activity is highest. Therefore, an excess of certain H+ ions in an acidic solution can lead to bonding between these ions and negative charges in the active site or other parts of an enzyme. This interaction can inhibit the matching process between the enzyme and its substrate, making it slow down or even prevent this enzyme activity. The same goes for a solution that has too many OH- ions, it will upset the enzymes activity. At extreme values of pH, the enzyme may even lose its shape and be denatured. 

Chromosomes coil up. The nucleolus and nucleus membrane break down and disappears. Microtubules will form at the poles of the cell which will create spindle fibers.

Chromosomes line up in the middle of the cell and spindle fibers connect to the centromeres. The microtubules will be put under tension to make sure attachment of chromosomes is correct.

The centromere divides, and chromatids separate. Two chromatids are made into a chromosome and then pulled to the oppose sides of the cell.

Spindle fibers disappear, and the chromosomes uncoil. Nucleolus forms as well as the nuclear membrane.

The cytoplasm will pinch in the center of the cell due to a ring of contractile proteins called actins and myosin. This creates a cleavage furrow which is where the cell will separate into two.

Vesicles will move to the center of the cell to form two layers of membrane which is called a cell plate. Pectin is brought in by daughter cells using exocytosis which forms a middle lamella that links the new cell wall. Cellulose is also brought in by exocytosis to form the cell wall.

Cancer although the cause for cancer generally unpredictable, it can occur for many reasons. Mutagens are physical or chemical agents that cause mutations which occur in the DNA of genes. For example, gamma rays and some radioactive substances. Oncogenes are genetic material that carries the ability to induce cancer such as mutated BRCA1 and BRCA2 genes as they will not be able to produce tumor suppressing proteins. Also, carcinogens which are substances that can directly cause cancer like tobacco smoke and PVC

However, this theory was proved false after Friedrich Wöhler synthesized urea using only inorganic compounds. Urea is a byproduct of urine that is used to rid the body of broken down proteins and ammonia. It is produced by the liver then is transported to the kidney. Now we know that it can be artificially made by reacting NH3 with carbon dioxide using a complex process of recirculation and evaporation. 

The G1 checkpoint where the cell determines whether or not it is going to divide. It checks the cell size, nutrients, growth factors, and if there is DNA damage. If the cell isn’t ready to divide, it will go in the G0 phase.

Before mitosis, the cell will have another check point to make sure cell division will run smoothly. The cell will check if the DNA is undamaged and correctly copied. If the cell is beyond repair, the cell will be destroyed to prevent cancer.

During mitosis, the cell will check to see if the sister chromatids are correctly attached to the spindle fibers. If a chromosome is misplaced, the cell will pause mitosis to allow the chromatid to attach.