Functions of Proteins

Question 1

How many gigabases in a human genome encodes for proteins?

Answer 1

out of 3.2 gigabases, only 1.1 to 1.4% encodes for proteins

Question 2

What percentage of the human genome are repeated sequences?

Answer 2

> 50% repeated sequences which are also known as junk or parasitic elements

Question 3

Elaboration and de novo Appearance of Human gene families:

What are the specific Vertebrate Abilities?

Answer 3

neuronal complexity, blood clotting and immune responses
Immunoglobulin domains greatly expanded: Antibodies, MHC, proteins, Antibody receptors and lymphocyte cell-surface proteins.

Question 4

Elaboration and de novo Appearance of Human gene families:

What are the increases in general capabilities?

Answer 4

Signalling, development, apoptosis, and transcriptional control.
30 fibroblast growth factors in the Human genome, 2 in fly and worm.
906 olfactory receptor genes and pseudogenes in the human genome.
90% not previously annotated and 60% have disrupted ORF’s indicating functional loss

Question 5

What are the common functions of human proteins?

Answer 5

Motion and Locomotion: Contractile proteins and molecular motors
Catalysis: Enzymes
Cell structure: Extracellular matrix, collagens, cellulose, vimentin, etc.
Transporters: Ca^2+ and ATPase
Ion channels: VOC, Chloride channel
Receptors and signalling proteins: GPCRs
Nutrients
Transcription factors: NF-kB, Antennapedia

Question 6

What % of Human genome encodes transcription factors

Answer 6

6%

Question 7

What % of Human genomes encodes for receptors?

Answer 7

5%

Question 8

What does the term Proteome mean?

Answer 8

Term used to describe entire protein complement of a cell

Question 9

Define Proteomics

Answer 9

Study of proteome

Question 10

Define Interactome

Answer 10

A whole set of molecular interactions in a given cell

Question 11

Define Post translation

Answer 11

Term used to describe entire protein complement of a cell

Question 12

What is Post translation important for?

Answer 12

For secreted proteins and membrane-bound proteins (GPCRs)

Question 13

Post translation modifications include?

Answer 13

Attachment of additional groups (e.g. carbohydrates)

Disulphide formation

Question 14

What are the common Post-translational Modifications?

Answer 14

Ribosome, Phosphorylation, Glycosylation, Ubiquitination, SUMOylation, Disulfide Bond, Acetylation, Lipidation, Methylation and Hydroxylation

Question 15

Post-translational modifications:

Addition of functional groups, what does this include?

Answer 15

Glycosylation (e.g N-linked)
Amidation of C-terminal
Palmitoylation

Question 16

Post-translational modifications:

What structural changes are involved?

Answer 16

Enzymatic cleavage
Disulphide bond formation
Phosphorylation

Question 17

Define Interactomes

Answer 17

An entire set of interactions inside a cell

Question 18

Define Party hubs

Answer 18

Proteins that interact with many partners most of the time

Question 19

Define Date hubs

Answer 19

Bind different partners, different times and places

Question 20

Explain the process of Apoptosis

Answer 20

1) Release of cytochrome c from the mitochondria
Binds to protein Apaf-1, causing it to assemble into seven-fold rings
2) Caspases, activated by binding to a ring of CARD domains on the assembled apoptosome

Question 21

Explain Ion (chloride) channels

Answer 21

Found in the membrane of many types of nerves
Pass through the nerve membrane, make gates allowing/blocking chloride ions.
Antibiotic Ivermectin attacks glutamate-gate chloride channels, paralysing parasitic worms

Question 22

Insulin is a protein hormone, what does it do?

Answer 22

Carries messages which shows the amount of sugar in the blood
Made in pancreas
Secreted to blood after meals when sugar levels are high

Question 23

How does insulin work in the body?

Answer 23

Binds to insulin receptors on the surface of liver, muscle and fat cells
Telling these organs to take glucous out of the blood, storing in the form of glycogen or fat

Question 24

What is Medical insulin used for?

Answer 24

Diabetes mellitus treated replacing the insulin that missing in the blood (injection).
Insulin from pigs differs from human insulin
Only one amino acid, therefore, are recognised by our own cells and may be used in therapy
Human insulin amino acids are used by engineering bacteria or yeast to produce a protein identical to our own

Question 25

How does insulin bind to insulin receptors?

Answer 25

Through a change in shape that is propagated inside the cell, activating the tyrosine kinases
Binds to the outer edge of the receptor, typically only binds to one side of the symmetrical receptor

Question 26

What is a Collagen protein?

Answer 26

One-quarter of all of the proteins in your body is collagen

It’s a major structural protein

Question 27

What does Collagen do?

Answer 27

Forms a molecular cable, strengthening the tendons and resilient sheets that support the skin and internal organs
Bones and teeth: Made by adding mineral crystals to collagens
provides structure to our bodies
Protecting and supporting the softer tissues and connecting them with skeleton

Question 28

Define post-translational Glycosylation?

Answer 28

Proteins and lipids on surfaces of red blood cells, post-translationally modified with carbohydrate chains

Question 29

How is blood type determined post-translational Glycosylation?

Answer 29

ABO blood type: Determined by the type of sugars used to build the carbohydrates
Carbohydrates built around a core of 5-13 sugars called H-antigens, ends in fructose sugar. O blood type, the story ends there.
For A and B, glycosyltransferase adds one more sugar to end.
Type A: N-acetylgalactosamine
Type B: Galactose

Question 30

What is the job of an Antibody?

Answer 30

Circulate in the blood
Finds a foreign object, binds tightly to the surface
Acts as marker alerting the other powerful defensive mechanisms available in the immune system
100,000,000 different types of antibodies

Question 31

What is the job of Motor protein Kinasin?

Answer 31

Walks along microtubules, dragging a cargo along
Composed of motor domain, splits ATP and converts the energy into motion and cargo binding domains, connects to object being moved
Composed of two chains