Proteins Flashcards

You may prefer our related Brainscape-certified flashcards:
1
Q

What are proteins formed from?

A

Amino acids.

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

How many bases code for one amino acid?

A

Three.

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

What is the bond formed between amino acids in a condensation reaction?

A

A peptide bond.

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

What is the primary structure of a protein?

A

The sequence and number of amino acids in a polypeptide chain.

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

What is the secondary structure of a protein?

A

The way the polypeptide chain twists into 3d shapes like alpha helices and beta pleated sheets due to weak hydrogen bonds forming between the N-H and C=O on amino acids.

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

What is the tertiary structure of a protein?

A

The way the protein folds into its complex, unique, 3D structure due to hydrogen bonds, ionic bonds, disulphide bridges and hydrophobic interactions of the R group of the amino acids.

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

What is the quaternary structure of a protein?

A

When a protein is made of 2 more polypeptide chains joined together. This sometimes involves a prosthetic group.

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

What is an example of a quaternary structure?

A

Haemoglobin, which has 4 tertiary structures bonded together with a prosthetic group of iron in the middle.

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

Which protein structure is only had by some proteins?

A

Quaternary structure.

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

How do you test for protein and what is the positive result?

A

Add biuret, will turn purple if positive.

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

What is activation energy?

A

The minimum amount of energy required for a chemical reaction to occur / the particles to collide.

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

What is a substrate?

A

The molecule which is complementary to the enzyme’s active site.

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

What is an active site?

A

Where the substrate binds to the enzyme.

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

As a substrate approaches its complementary enzyme - what happens?

A

The proximity of the substrate causes a conformational change to the active site and tertiary structure of the entire enzyme (change of shape) which allows the active site to become functional and an enzyme-substrate complex to form.

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

What factors affect rate of reaction?

A
  • Temperature
  • Concentration
  • Non-competitive inhibition
  • Competitive inhibition
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What happens to enzymes at high temperatures?

A

They will denature (a conformational change in tertiary structure due to breaking bonds).

17
Q

How does temperature affect rate of reaction?

A

At low temperatures, substances have less kinetic energy, therefore the enzyme and substrate will be less likely to collide and form an enzyme-substrate complex which means enzyme activity decreases.
As temperature increases, rate of reaction increases until the temperatures gets too high and enzymes denature, meaning their active site is no longer complementary to the substrate and cannot form an enzyme-substrate complex.

18
Q

How does pH affect enzymes?

A
  • A change in pH alters the charges of the amino acids that make up the active site, which prevents an enzyme substrate-complex forming.
  • A significant change in the pH can also cause the ionic and disulphide bridges to be disrupted.