Lysosomes are part of the body's defense mechanism. It contains digestive enzymes which can digest bacteria.

Fun Fact: The enzyme is called hydrolytic enzymes.

Role I: Destroy and Digest Pathogens such as bacteria & viruses.

Role II: Aid breaking down & disposal of waste products. E.g. Bacterial / Viral DNA, Worn-out cell parts & debris, proteins, nucleic acids (stores genetic info. ) & Sugar (Could be excess), Carbohydrates & Lipids and so on.

Role III: Cholesterol Transport (Requires Transport Proteins)

There are many more roles played by Lysosomes. The aforementioned roles

Role IV: Detoxication

For further information, please visit:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5201012/

controls entry and exit of material

• Nuclear pore: allows large molecules passage

• Nucleolus: manufacture rRNA

Function: Acting as a site for protein synthesis.

2. Consists of 1 Large sub unit & 1 small subunit

Functions:

Small subunit: Reads the genetic information and later binds to mRNA.

Large subunit: Catalyses peptide bonds and binds to tRNA

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Fun Facts:

1. Ribosomes are found in both prokaryotic or eukaryotic organisms.

2. Amino Acids --> Multiple Amino Acids linked together by Peptide Bonds (Forming Massive Chains)--> Proteins

Sneak Peak at Protein Synthesis:

1. Transcription – During Which a strand of mRNA is synthesized from a particular gene template.

2. Translation – During which the mRNA attaches to the ribosome, which recruits tRNAs carrying amino acids in order to make a polypeptide.

   
   

   
   

   
   

   
   

   
   

   
   

   
   

   
   

   (Extracted from Study Mind : DNA - Protein Synthesis: Translation (GCSE Biology))

   
   

   Useful Link:

   1.Study Mind:

   (https://studymind.co.uk/notes/protein-synthesis-translation/#:~:text=Transcription%20%E2%80%93%20during%20which%20a%20strand,order%20to%20make%20a%20polypeptide.)

   2.geeksforgeeks.org - Ribosomes

   https://www.geeksforgeeks.org/ribosomes/#ribosome-structure

Adaptive Features & Functions:

I.Phospholipid-Bilayers: Form by hydrophilic phosphate heads & hydrophobic lipid tails. Thus being selectively permeable.

Ia)Simple Diffusion: Small & Non-polar Molecules: Oxygen, CO2, lipid-soluble substances.

Ib) All Channel & Most Carrier Proteins:

Facilitated Diffusion: Charged Molecules & Polar Molecules: Carbohydrates, Amino Acids, Nucleoside (A structural sub-unit of Nucleic Acids), Ions

*Both Channel & Carrier Proteins are selective*

(Integral Proteins)

Ic)Carrier Proteins (Channel Proteins is always Passive Transport):

Active Transport: Large & Polar Molecules: Amino Acids (Polar but not charged), Glucose, Ions

II: Cell Recognition:

IIa):Glycoproteins

IIb):Glycolipids

III: Cell Sturcture:

IIIa): Phospholipid Bilayer

IIIb): Glycolipids

IIIc): Cholesterol: Prevents leakage of water & provide stability.

General Roles:

• Selectively exchange substances,

• Absorb nutrients

• Excrete metabolic waste

• Secrete and transport proteins

Glucose -> Glycolysis -> 2 Pyruvate Acid -> 2 Pyruvate + 2ATP + 2 NADH

Product: 2 Pyruvate, 2 ATP (net gain*), 2 NADH

Site: Cytoplasm (Outside of Mitochondrion & not an organelle)

Conditions: With Oxygen Supply,

Pyruvate -with coenzyme A -> Acetyl CoA

+ CO2

Product Acetyl CoA & CO2

*Please note that Acetyl CoA will later be used in the Krebs Cycle in Mitochondrion. *

Extra Knowledge Point:

Conditions: Without Oxygen Supply,

Anaerobic respiration: Fermentation -> Ethanol (Yeast/Plant Cells) // Lactate / lactic acid (Muscle Cells/ lactic acid bacteria)

Krebs Cycle Reaction:

1. Acetyl CoA (2C) + 4C Compound (oxaloacetate)-> 6C Compound (Citrate)

2. Citrate Isocitrate (Isomer of Citrate) -> 5C Molecule + CO2 + NADH

Product: CO2 + NADH

(NAD+ being reduced by H+)

3. 5C Compound (a-ketoglutarate) -> 4C Copmound + CO2 + NADH+ ATP + FADH

Product: 4C Compound (fumarate) ,CO2, NADH, ATP, FADH

(NAD+ being reduced by H+)

(ATP convert from ADP)

(FADH being converted from FAD, during the above process)

Regeneration of 4C Compound:

4. 4C Compound (fumarate) -> 4C Compound (malate)

5. 4C Compound (malate) → 4C Compound (oxaloacetate) + NADH

Product: 4C Compound ( oxalocetate), NADH

[Regeneration of this Compound via oxidation of malate & NAD+ is reduced to NADH by H+]

After 1 Cycle Is Completed:

Total Number of Desired Products:

ATP: 1

FADH: 1

NADH: 3

CO2: 2

---------------------------------Thus after the cycle has been completed twice:

We will have:

2 ATP, 2 FADH, 6 NADH, 4CO2

Final Stage of Aerobic Respiration:

All FADH/ FADH2 and NADH will be converted to produce ATP via oxidative phosphorylation.

As the name included, "Oxidative" Thus oxygen is required for this process. It acts as the electron acceptor & later form water with hydrogen ions (picks up protons)

Site: Inner Membrane of Mitochondrion// Inner Mitochondrial Membrane

Producing ATP by converting all FADH & NADH

Total Number of ATP, FADH, NADH produced throughout the anaerobic respiration up till the Krebs Cycle:

Glycolysis: 2 ATP ; 2NADH ; 2 Pyruvate

Link Reaction: 0 ATP ; 2 NADH (1 per each Pyruvate), 2 Acetyl CoA ( 1 per each pyruvate); 2CO2 (by-product)

Kreb's Cycle/Citric Acid Cycle: 2 ATP, 2 FADH2, 6 NADH, 4 CO2

[1 ATP, 1 FADH, 1 NADH, 2 CO2 from each Acetyl CoA/ 1 Cycle]

Oxidative Reaction: 34 ATP

(Each FADH2 give 2 ATP, Each NADH gives 3 ATP)

[A total of 2 FADH2 & 10 NADH = 2x2+10x3 = 34 ATP]

Thus overall, in aerobic respiration: We have a total of 38 ATP being produced.*

For Further Information:

https://www.tuttee.co/blog/hkdse-biology-aerobic-respiration

• provide a large surface area for the synthesis of proteins and glycoproteins and a pathway for the transport of materials

• synthesis, storing, and transport of lipids and carbohydrates