proteins

Question 1

what are proteins?

Answer 1

1 or more polypeptide chains folded into a 3D structure shape

Question 2

what are the 3 groups in an amino acid?

Answer 2

• amino group
• carboxylic acid group
• residual group
• H atom

Question 3

what is a polypeptide?

Answer 3

a chain of amino acids help by peptide bonds

Question 4

how are amino acids bonded together

Answer 4

the carboxyl group from one is bonded via a condensation reaction to the amino group of another to form a peptide bond and make a dipeptide structure

Question 5

what are the 4 structural stages of a protein?

Answer 5

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

Question 6

what are the 2 types of proteins?

Answer 6

Globular and fibrous

Question 7

what is the first stage of protein structure?

Answer 7

Primary:
amino acids are orders

Question 8

whats is the second stage of protein structure?

Answer 8

secondary:
structure is determined and stabilised by hydrogen bond and some folds appear for example alpha- helix and beta- pleated sheets

Question 9

whats is the third stage of protein structure?

Answer 9

tertiary:
the overall 3D shape is determined and multiple fold are formed
its now contains 3 types of bonds: ionic, H and disulphide bonds and sometimes hydrophilic and hydrophobic interactions

Question 10

what happens in the 4th stage of protein structure?

Answer 10

quaternary: when the a polypeptide joins onto another polypeptide

Question 11

what is the structure of haemoglobin and what is it used for?

Answer 11

• 4x prothetic group called heam
• globular
• 2x alpha subunits
• 2x beta subunits
• carry oxygen in blood

Question 12

what is the structure of collagen and what is it used for?

Answer 12

• fibrous
• made of 3 polypeptide chains that are around 1000 amino acids long
• a helix shape thats held by H bonds and ionic cross links
• for strength in cartilage, bones, tendons…