Biochemistry of Macromolecules

What is Biochemistry?

Study of chemical processes w/in and relating to living organisms

What are Antibodies?

Used by the body to identify and neutralize pathogens.​

What are Contractile Proteins used for?

Movement - Actin and Myosin in muscle contraction and movement

What are Enzymes?

Proteins that catalyse biochemical reactions

What are Hormonal Proteins?

Messenger proteins which help to coordinate certain bodily activities​

What are Structural Proteins?

Fibrous proteins that provide support

What is the role of Collagen and Elastin?

Provide support for connective tissues such as tendons/ligaments

What are Transport Proteins?

Carrier proteins which move molecules from 1 place to another around the body

Initation of Translation

• Binding 1

• Recognition

• Binding 2

• Subunit

• Small ribosome binds to mRNA

• Start codon (AUG) is recognised

• tRNA carrying methionine binds to start codon

• Large ribosomal subunit joins

Elongation of Translation

• Bringining amino acids

• Role of ribosome

• Movement of ribosomes

• New tRNA

• tRNA brings specific amino acids matching the codons in mRNA.​

• Ribosome links amino acids together (peptide bonds)​

• Ribosome moves along mRNA, left to right. reading codons​

• A new tRNA binds the mRNA and the previously bound tRNA detaches

Termination of Translation

• Stop codon

• Dissociation 1

• Dissociation 2

• Release

• Stop codon is reached.​

• Ribosome dissociates from mRNA. ​

• tRNA dissociates from mRNA too. ​

• Newly made protein is released into cytoplasm

How are the 20 standard amino acids organised?

9 essential, 11 non-essential

How are Essential and Non-essential Amino Acids different?

• Essential

• Non-essential

• Must obtain these amino acids in our diets

• We can synthesize

How do Amino Acids differ?

Differ in side chains

Standard Amino Acids

• Derive from where?

• Genetic Code

• Derive from the codons of the universal genetic code ​

• Genetic code is nearly identical w/ few minor variations, supports theory that life on Earth descended from a single ancestor ​

• However there are also unusual “non-standard” amino acids​

Non-Standard Amino Acids

• Derived from where?

• Examples

• 3 that stand out

• Derived from modification once a protein has been synthesized - post-translational modifications

• Methylation, acetylation, phosphorylation

• There are 3 that are not encoded in the universal genetic code and are incorporated into proteins by unique synthetic mechanisms