proteins

Question 1

what is an amino acid

Answer 1

a basic unit of a protein

Question 2

there are 20 different amino acids: what are the 3 types?

Answer 2

1. non-polar
2. polar
3. electrically charged

Question 3

where does the formation of a peptide bond take place

Answer 3

on a ribosome

Question 4

how is a peptide bond formed?

Answer 4

• a carboxylic acid condenses with can amino group + the release of water

Question 5

what are the 4 types of protein structures

Answer 5

1. primary structure
2. secondary structure
3. tertiary structure
4. quaternary structure

Question 6

why does each protein have a unique structure?

Answer 6

because it is based upon the sequence of amino acids joined together.

Question 7

name 2 types of proteins

Answer 7

1. globular protein ]
2. fiberous protein

Question 8

globular protein function & example

Answer 8

carry out metabolic functions e.g. enzymes and heamaglobin

Question 9

fiberous protein function & example

Answer 9

have structural functions e.g. collagen

Question 10

fiberous protein structure

Answer 10

• does not have tertiary structure
• long fibres or sheets in place
• insoluble in water
• perform structural functions
• length of polypeptide chain may vary in two samples of the same fiberous sample

Question 11

globular protein structure

Answer 11

• have a tertiary structure
• spherical shape
• dissolve in water
• length of polypeptide chain is always identical in 2 samples of the same globular protein
• perform metabolic functions

Question 12

primary protein structure

Answer 12

• a sequence of amino acids in a polypeptide chain
• held together with peptide bonds

Question 13

secondary protein structure

Answer 13

• weak hydrogen bonds between orm between the carbonyl O of one amino acid and the amino H of another.
• this pulls the polypeptide chain into either an alpha helix coil or a beta pleated sheet
• the way the bonds form determine the shape

Question 14

tertiary protein structure

Answer 14

• further folding of the whole polypeptide chain the give a very specific 3D shape/structure
• each shape/structure= a different function
• they are held together by a number of different bonds between the R groups of amino acids

Question 15

quaternary protein structure

Answer 15

• association with different polypeptide chains= quaternary structute
• form a large complex protein molecule
• held togther with the 4 bonds from tertiary structure