PROTEINS

Question 1

amino acids contain

Answer 1

amino group
acid group

Question 2

General structure of an amino acid

Answer 2

hydrogen
amino central carboxyl acid carbon group
group
R group

Question 3

How many R groups and amino acids

Answer 3

20

Question 4

What reaction / bond joins amino acids

Answer 4

peptide bond
condensation reaction

Question 5

What does a peptide bond look like

Answer 5

O=C-N-H

Question 6

2 amino acids

Answer 6

Dipeptide

Question 7

Many amino acids

Answer 7

polypeptide

Question 8

the beginning and end of a polypeptide chain is called

Answer 8

N terminus - H2N
C terminus - COOH

Question 9

A sequence of amino acids is based of

Answer 9

The sequence of bases in DNA

Question 10

Primary structure

Answer 10

The sequence of amino acids in the polypeptide chains which determine the structure
sequence
number and
type
NOT number oreder type

Question 11

Secondary structure

Answer 11

The structure held together by hydrogen bonds between carboxyl groups and amino acid groups in the polypeptide backbone
These are Alpha helix spirals and Beta [pleated] sheets

Question 12

Alpha helix

Answer 12

H bonds are formed between non-adjacent amino acids forming into a helix spiral
Alpha helix is very strong and stable structure

Question 13

What elements in which groups have H bonds between them

Answer 13

The O in the carboxyl group and one of the H in the amino group

Question 14

Beta [pleated] sheet

Answer 14

polypeptide chains are zigzagged forming a sheet of antiparallel strands held together by hydrogen bonds

Question 15

Tertiary structure

Answer 15

The compact globular structure is formed by folding a polypeptide chain
They are responsible for the functions and properties of the proteins eg. active sit of the enzyme

Question 16

How is the tertiary structure held together

Answer 16

By bonds between the R groups of amino acids, so the shape of the protein is dependant on the order of the amino acids and the type of amino acid

Question 17

What are the 3 bonds that make the globular structure

Answer 17

Weak H bonds
Ionic bonds
Strong Sulphur bridges (covalent S-S bonds between two cysteine amino acids)

Question 18

What causes inwards and outwards protein folding

Answer 18

Hydrophobic interactions (inward)
Hydrophilic interactions (outward)

Question 19

Quaternary structure

Answer 19

the interactions and numbers of polypeptide chains in a protein

Question 20

Examples of quaternary structure

Answer 20

ATP
Hemoglobin
Collagen

Question 21

Globular and Fibrous proteins

Answer 21

The final 3D shape of a protein

Question 22

globular protein examples

Answer 22

Most proteins
-enzymes
-membrane proteins
-receptors
-storage proteins

Question 23

fibrous proteins roles

Answer 23

long and thin usually with structural roles

Question 24

fibrous proteins examples

Answer 24

-collagen
-keratin
-cytoskeleton

Question 25

What bonds and structures are broken when an enzyme denatures and what remains

Answer 25

-Secondary,tertiary and quaternary structures are broken due to the breaking of Hydrogen bonds
-Primary structure remains intact along with the covalent bonds and disulphide bridges

Question 26

What is the biochemical test for proteins

Answer 26

1-Add equal volumes of sodium hydroxide to an aqueous protein sample
2-Add a few drops of aqueous copper sulfate
3-When mixed the solution turns purple when the proteins present
-NaH + H2O
-add CuSO4 + H2O
-purple