Brainscape's Knowledge GenomeTM

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


See full index

Biological Molecules > Proteins > Flashcards

Proteins Flashcards

You may prefer our related Brainscape-certified flashcards:
Organic Chemistry 101 flashcards
1
Q

What is the structure of a polypeptide?

A

Many amino acids joined by peptide bonds between amine group of one and carboxyl group of another

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

What is the structure of amino acids?

A

Central C atom with amine, carboxyl, R, and H attached
H2NCHRCOOH

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

What is the purpose of the R group?

A

Makes each amino acid different
Determines how the amino acid interacts & bonds with other amino acids in the polypeptide

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

How many different amino acids are there?

A

20 common in all organisms, 10 of which can’t be made by humans so needs to be obtained by diet

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

What is the function of structural proteins?

A

Fibrous
Long, strong chains held parallel by cross links
Collagen & keratin

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

What is the function of transport proteins?

A

Globular
Fold up due to hydrophobic & hydrophilic amino acids
Transports molecules & ions across membranes

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

What are the 3 steps to test for a protein?

A

Add distilled water & Biuret solution (NaOH & copper II sulfate) to sample
Shake & leave upright for 5 mins
If positive blue to violet

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

What is the primary structure of a protein?

A

Sequence of amino acids in the polypeptide chain

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

What determines the primary structure?

A

The gene encoding the protein so a change to nucleotide sequence could cause a different amino acid to be added, causing a different shape protein with a different structure/function

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

What is the secondary structure of a protein?

A

Amino acids in the chain form hydrogen bonds with each other
Coils into alpha helix or folds into beta pleated sheets

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

What is the stability of the secondary structure?

A

It is stable, because although individual hydrogen bonds are quite weak, there are many so it’s stronger/more stable
Stability decreases by temp/pH etc

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

What is the tertiary structure of a protein?

A

Further folding into a unique 3D shape due to interactions between R groups (ionic bonds, hydrogen bonds, disulfide bridges)

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

What is the quaternary structure of a protein?

A

Multiple 3D polypeptides coming together

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

What is an enzyme?

A

Biological catalyst that lowers the AE of chemical reactions by binding to substrate & making bond breaking/making process happen easier

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

What is the active site?

A

Area that is complementary in shape to a specific substrate, determined by tertiary structure

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

What is the lock & key model?

A

Active site is fixed shape that substrate fits perfectly into
Random collisions allow for E-S complexed to form
Charged groups in active site distort substrate, lowering AE, products release

17
Q

What is the induced fit model?

A

When enzyme & substrate come together, shift in shape of active site
Enzyme moulds around substrate, strains bonds, easier to break, products released

18
Q

What is the effect of low temp on enzyme activity

A

Not enough KE for successful collisions between enzyme & substrate

19
Q

What is the effect of high temp on enzyme activity?

A

Enzyme denatures, active site changes shape

20
Q

What is the effect of insufficient substrate concentration on rate?

A

Fewer collisions, lower rate

21
Q

What is the effect of insufficient enzyme concentration on rate?

A

Active sites saturated, can’t work faster, rate plateaus

22
Q

What is the effect of pH on enzyme activity?

A

Changes number of H+ or OH-
Interact with charges in active site amino acids, breaks bond in tertiary structure, denatures

23
Q

How do competitive inhibitors work?

A

Same shape as substrate so binds to active site, preventing reaction.
Adding more substrate floods/out competes, knocks out of active site

24
Q

How do non-competitive inhibitors work?

A

Binds to enzyme at allosteric site, changes active site shape permanently so substrate can’t bind even if extra is added

25
Q

What is the equation for rate of reaction?

A

Increase in product or decrease in reactant/ Time

Biological Molecules (6 decks)

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