Proteins Flashcards Preview

A Level Biology: Topic 1 (Edexcel) > Proteins > Flashcards

Flashcards in Proteins Deck (29):
1

What monomers make up proteins?

Amino acids

2

What is the basic structure of an amino acid?

Amino group
Carboxyl group
R group (variable)

3

What is the primary structure of a protein?

Sequence of amino acids joined by peptide bonds between the amino and carboxyl groups

4

What bonds are found in the primary structure of a protein?

Peptide bonds

5

What is the secondary structure of a protein?

The arrangement of the polypeptide chain into an alpha helix or beta pleated sheet.

6

What is the general strucute of an alpha helix in the secondary structure of a protein?

Spiral coil with the peptide bonds forming the backbone and the R groups sticking out

7

What bonds are in the beta pleated sheet of the secondary structure?

Hydrogen bonds

8

How do hydrogen bonds form?

Small negative charge on the oxygen atom in the carboxyl group
Positive charge in the hydrogen atom of the amino group

9

What is the tertiary structure of a protein?

The alpha helixes and beta pleated sheets are folded into complex shapes with disulphide and ionic bonds

10

What bonds form in the tertiary structure?

Disulphide and ionic bonds

11

How do disulphide bonds form?

When two cysteine molocules are close together and an oxidation reaction occurs

12

How are ionic bonds formed?

Form between the strongly positive and negative amino acid side chains

13

What is quaternary structure?

Seperate polypeptide chains fit together in 3D

14

What conditions affect the bonds of a protein?

pH
Tempreture

15

What happens when a protein denatures?

Bonds break and the protein changes shape

16

What is a fibrous protein?

A protein with no tertiary structure with long paralell polypeptide chains and occasional cross linkages

17

What makes fibrous proteins suited to their function?

Insoluable
Tough
Long

18

What are the function of some fibrous proteins?

Connective tissue in tendons
Bone matrix
Structure of muscles

19

What kind of protein is collagen?

Fibrous protein

20

What is the function of collagen?

To give strength to tendons, ligaments, bones and skin

21

What is the general structure of collagen?

Three polypeptide chains arranged in a triple helix with many hydrogen bonds

22

What are the characteristics of globular proteins?

Spherical shapes with complex tertiary structures

23

What is a conjugated protein?

When a protein has a prostetic group

24

What are two kinds of conjugated proteins?

Glycoproteins
Lipoproteins

25

What is a glycoprotein?

A protein with a carbohydrate prostetic group

26

What is a lipoprotein?

A protein conjugated with lipids

27

What two types of lipoproteins are found in the blood?

LDL
HDL

28

What is LDL?

Low density liproproteins

29

What is HDL?

High density liproproteins