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Flashcards in Proteins Deck (27)
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1
Q

Name 7 types of Amino Acid

A
  • Aliphatic
  • Aromatic
  • Uncharged Polar
  • Other (Proline)
  • Sulphur containing
  • Acidic
  • Basic
2
Q

Explain an Aliphatic Amino Acid

A

R group is made up of straight or branched carbon chains

3
Q

Explain an aromatic Amino Acid

A

R group contains Phenyl (benzene) groups

4
Q

Explain an uncharged Polar Amino Acid

A

R group is uncharged but polar so has a localised charge making them capable of hydrogen bonding and hydrophilic

5
Q

Explain Acidic Amino Acids

A

Contains COOH groups which can lose protons making them acidic

6
Q

Explain Basic Amino Acids

A

Contain Nitrogen groups that resemble ammonia and can accept protons making them basic

7
Q

Define Primary Protein Structure

A

The sequence of amino acid residues in a linear polypeptide chain

8
Q

Define Secondary Protein Structure

A

The spatial arrangement of amino acid residues close to eachother in the linear polypeptide chain.

9
Q

Name two structures created by arrangement of the secondary structure

A

The Alpha Helix and Beta Pleated sheets

10
Q

What links amino acid residues in the secondary structure?

A

Hyrdogen Bonds

11
Q

Define Tertiary Structure

A

The spatial arrangement of amino acid residues far apart in the linear polypeptide chain.

12
Q

What forces hold the tertiary structure in place?

A
  • Numerous, weak van der waals forces
  • Hydrogen Bonds
  • Rare but strong ionic interaction between oppositely charged ions
  • Disulphide bridges, covalent bonds between sulphur ions in two cysteine residues
  • Hydrophobic interactions, intra-polypeptide interactions which occur in an enviroment within proteins in which water is excluded. Cause the protein to coil up so the hydrophobic residues face inward and teh hydrophilic outward.
13
Q

Define Quaternary Structure

A

The spatial arrangement of individual polypeptide chains in a multi-subunit protein

14
Q

How does denaturation affect protein stucture?

A

It can disrupt or break bonds in the secondary and tertiary structures, changing the shape and function of the protein. However it is not strong enough to break peptide bonds so the primary structure is unaffected.

15
Q

Name 6 causes of Denaturation

A
Heat
Acid
Solvents
Crosslinking reagents (formaldehyde)
Chaotropic agents (Urea)
Disulphide bond reducers.
16
Q

Name 4 effects of Denaturation

A

Improved Digestibility
Reduced water binding capability
Loss of biological activity
Decreased Solubility

17
Q

Define a Glycoprotein

A

A compound composed of a protein and a carbohydrate. Glycosylation where a sugar molecule binds to an amino acid in the protein.

18
Q

What are the 5 roles of Glycoproteins?

A
Protein Stabilisation
Signalling
Cell recognition
Affects Solubility
Protein Orientation
19
Q

Define a metalloprotein

A

A protein molecule with a bound metal ion such as haemoglobin

20
Q

Name 4 roles of metalloproteins

A

Transport
Enzymes
Signalling
Storage

21
Q

Define a Lipoprotein

A

A protein bound covently or non-covently to lipids.

22
Q

Whats the function of lipoproteins?

A

To transport not water soluble fats and cholestorol around the blood stream.

23
Q

Define Co-operative binding

A

In a multi-subunit protein binding to one of the chains causes the shape of the others to alter making it easier for them to bind.

24
Q

Name the 5 functions of globular Proteins

A
  • Enzymes
  • Hormones
  • Transporters
  • AMino acid stocks
  • Structural
25
Q

Name the 4 structural functions of fibrous proteins

A

Bone Matrices
Muscle Fibre
tendons
Connective Tissue

26
Q

Compare the structures of Globular and Firbous proteins

A

Globular proteins are made up of interwoven polypeptide chains.
Fibrous proteins are made up of helixes formed from polypeptide chains wound round more helixes to form strong fibres and held together by H bonds.

27
Q

Explain 4 Properties of Collagen

A
  • Fibrous Protein
  • Makes up 25% of our prtein
  • High tensile Strength
  • is made from a glycine-X-proline repeating unit