Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

MD2001 Week 3 > Structure of Proteins 1 > Flashcards

Structure of Proteins 1 Flashcards

1
Q

What is the most abundant protein in mammals?

A

Collagen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the five functions of proteins?

A

Provide structure

Transport molecules

Defence

Biological catalysts

Regulation of genes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the structure of haemoglobin?

A

4 protein subunits per molecule

Haem bound to each sub unit that allows one oxygen to bind

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the structure of haem?

A

Porphyrin ring surrounded an atom of iron

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the structure of LDL?

A

Phospholipid cell and a single molecule of apolipoprotein B

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the function of LDL?

A

Used to transport cholesterol between cells via the circulatory system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the structure of an antibody?

A

Two heavy and two light chains- linked by disulphide bridges

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the function of lysozyme?

A

Catalyses the cutting of polysaccharide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Describe the function of the lac repressor?

A

When lactose binds the lac repressor, it undergoes a conformational change resulting unbinding from the portion of DNA

This then allows transcription of genes that code for proteins that will metabolise lactose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the primary structure of proteins?

A

Sequence of amino acids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the secondary structure of proteins?

A

Locally and in specific regions, the chain folds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what is the tertiary structure?

A

The overall folding of the protein

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the quaternary structure?

A

Having more than one sub unit

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

How many amino acids are there?

A

20

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are the different classes of hydrophilic amino acids?

A

Basic

Acidic

Polar

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Example of basic AA?

A

Lysine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Example of acidic AA?

A

Aspartate

18
Q

Example of polar AA?

A

Serine

19
Q

What is the general structure of hydrophobic amino acids?

A

Long carbon chains

20
Q

Example of hydrophobic amino acids?

A

Alanine

Valine

Isoleucine

21
Q

what are the three “special” amino acids?

A

Cysteine

Glycine

Proline

22
Q

What is special about cysteine?

A

Can form covalent disulphide bridges

23
Q

What is special about glycine?

A

Smallest amino acid and can fit into tight spaces

24
Q

What is special about proline?

A

The side chain form a bond with its self causing a kink in the protein chain

25
Q

What is the definition of an acid?

A

A molecule that tends to release a hydrogen ion

26
Q

What is the definition of a base?

A

A molecule that readily combines with a hydrogen ion

27
Q

What is the pKa of an acid equal to?

A

Equal to the pH at which half the molecules are disassociated

28
Q

How to convert Ka to pKa?

A

pKa=-log(Ka)

29
Q

What is Ka?

A

Equilibrium constant

30
Q

How do you find the pH of a reaction?

A

Hasselbach equation

31
Q

What is the biological significance of pKa?

A

Close to the pKa, small changes in pH can cause significant changes in the charge carried

32
Q

Example where a change in pKa is useful in the body

A

When LDL binds to the LDL receptor, it is transported into the cell via an endosome

The pH of the endosome then changes causing an change in pKa due to the presence of histidine residues

This then means the LDL can no longer bind and is passed to a lysosome

33
Q

What are the constraints on a peptide bond?

A

Peptide bonds do no permit rotation

34
Q

What causes the constraints in rotation in a peptide bond?

A

The variable double bonds coming from the alpha carbon

This limits the number of 3-dimensional conformations possible for a polypeptide

35
Q

What are the three main types of secondary structure?

A

alpha helix

beta sheet

Loops and bends

36
Q

What is the average number of amino acid residues in a alpha helix?

A

3.6

37
Q

Where is the helix shape stabilized by?

A

Stabilized by H-bonds between amino and carboxyl groups of every 4th amino acid

38
Q

Describe beta sheets

A

Extended stretches of 5 or more amino acids are called beta-strands

39
Q

What are the two different variations of beta sheets?

A

Parallel and Anti-parallel beta sheets

40
Q

What is the difference between parallel and anti-parallel beta sheets?

A

Adjacent strands run the same way in parallel C-N

41
Q

How many amino acids are required to cause a bend/loop?

A

4

42
Q

What is often found in bends and loops?

A

Proline

MD2001 Week 3 (8 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions