Brainscape's Knowledge GenomeTM

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


See full index

1) Biochemistry I > Membrane & Fibrous Proteins > Flashcards

Membrane & Fibrous Proteins Flashcards

1
Q

Where can a membrane protein be located?

A

Outside, through or on the inner-surface of the cell

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

What are the two main functions of membrane protein in tissues?

A
  • Critical to give your cells identity

- Moving nutrients and waste in/out of the cell

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

Where are peripheral membrane proteins found?

A

In and out of the cell (NOT THROUGH)

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

Name the 3 ways peripheral membrane proteins bind to the membrane.

A

1) Lipid tail, which inserts into the membrane
2) Protein-protein interactions (anchored to membrane)
3) Electrostatic interactions with phospholipid head group

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

Where are integral membrane proteins located?

A

INSERT completely (partly inside and outside the cell)

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

What are the functions of integral membrane proteins?

A

They can shut down/turn on the expression of a gene

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

What do you need to traverse the lipid bilayer?

A

A transmembrane domain that traverses the lipid bilayer

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

What are TMDs made up of? (Transmembrane domain)

A

JUST hydrophobic amino acids

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

What is the Kyte-Doolittle plot’s function?

A

To plot hydrophilicity as a function of residue number.

To figure out the function, where it acts

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

What does above 0 mean? And below?

A

Above: hydrophobic (TMD)
Below: hydrophilic

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

Are fibrous proteins soluble in water?

A

They are non-soluble

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

What is the function of a-keratin?

A

Tough, rigid (nails, horns)

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

What is the structure of a-keratin?

A

Cross-linked a-helices

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

What is the function of collagen?

A

Tensile strength (tendons, cartilage)

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

What is the structure of collagen?

A

Cross-linked triple helices

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

What is the structure of silk fibroin?

A

Non-covalently held B-sheets and van der waals

17
Q

What is the function of silk fibroin?

A

Soft, flexible (non-stretchy)

18
Q

What gives a-keratin its great strength?

A

Covalent disulfide bonds

19
Q

Describe the 4 steps it takes to become a-keratin.

A

1) Alpha helix (long)
2) Two alpha-helices intertwine
3) Binds with another a-helix intertwined in a head to tail fashion (protofilament)
4) + Intertwinning and disulfide bridges (protofibril)

20
Q

The single a-keratin subunit is ____ handed.

A

Right

21
Q

Two subunits of a-keratin will form a ____ handed a-helix.

A

Left

22
Q

A-keratin is rich in ____? What does that explain?

A

Non-polar amino acids (hydrophobic), explains why it wraps around

23
Q

What is collagen important for?

A

Connective tissue (tendons, cartilage, bones)

24
Q

What is a collagen chain rich in?

A

Glycine and Proline

25
Q

One collagen chain is _____ handed.

A

Left

26
Q

Three intertwined collagen chains are ____ handed.

A

Right

27
Q

Name a characteristic of collagen’s triple helix bond.

A

Higher tensile strength than a steel wire of equal cross section

28
Q

What force holds collagen together?

A

Hydrogen bonds

29
Q

A lack of what can affect collagen strength? Why?

A

Vitamin C, less hydroxy proline, less strength

30
Q

What makes aging skin rough?

A

The number of crosslinks in your skin increases as you age

31
Q

Explain how fibrils are laid in the tendon, cornea, and skin.

A

Tendon (linear)
Cornea (criss-cross)
Skin (random)

32
Q

What influences the strength of collagen fibrils?

A

The way fibres are laid down.

33
Q

What do proteins sometimes require to function?

A

Cofactor

34
Q

Name 2 protein cofactor groups.

A

Prosthetic groups and metals

35
Q

What are prosthetic cofactor groups made of?

A

Organic compounds

36
Q

Name 4 ways protein structure can be denatured.

A

1) Heat/Cold
2) Extremes in pH
3) Organic solvents
4) Detergents

37
Q

How would you transform straight hair into curly?

A

Reducing agent that cleaves the disulfide bonds between the a-keratin. Curler mechanically changes the structure, oxidizing agent promotes the formation of a set of disulfide bonds
CURLY HAIR HAS MORE DISULFIDE BONDS

38
Q

Is a-keratin made of a-helices? Is collagen?

A

a-keratin: yes

collagen: NO, a chains

39
Q

What do TMDs require for solubility in aqueous solutions? Why?

A
  • Require detergents or organic solvents

- Because they are hydrophobic

1) Biochemistry I (12 decks)

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