UNIT 2- PROTEINS

Question 1

How can fibrous proteins be described?

give 2 examples in the body

Answer 1

Long, spiral chains that are folded to form strong structures
Hair and fingernails

Question 2

What are the roles of proteins in the body?

Answer 2

Regulate life processes
Structure

Question 3

How are proteins made?

Answer 3

Condensation reactions

Question 4

Name the structure and the functional groups present in proteins?

Answer 4

Amine/ peptide -NH2
Carboxylique acid -COOH

Question 5

Describe what the peptide link looks like and how it is formed?

Answer 5

N is attached to an H and the N is attached to a C which has a double bond to an O
The -OH is taken away from the carboxylic acid group and a H is taken away from the anode group

Question 6

What are essential amino acids

Answer 6

The amino acids that cannot be produced from the body alone
It has to be synthesised

Question 7

How are proteins broken down?

Answer 7

HYDROLYSIS
it breaks the peptide links which separates the protein

Question 8

Digestion of the proteins- what is the role of enzymes in this?

Answer 8

They break the proteins that we eat into animo acids by hydrolysis
Transported in the blood

Question 9

What alter flavours?

Answer 9

Cooking methods

Question 10

What changes the structure of food?

Answer 10

Heat

Question 11

Name the two types of protein molecules?

Answer 11

Fibrous
Globular

Question 12

Describe Fibrous Proteins

Answer 12

Generally insoluble in water
Long spiral shapes folded to form a strong structure
Major structural material

Question 13

Describe globular proteins

Answer 13

Generally soluble in water
Regulation of life processes
Spiral chains folded into spherical shapes

Question 14

How are the fibrous and globular proteins held in shape

Answer 14

Held in these shapes by intermolecular bonding between the side chains of the amino acids involved

Question 15

Where can hydrogen bonds be made?

Answer 15

The rule is from a hydrogen connected to an oxygen OR nitrogen connected to another oxygen (includes the carbonyl oxygen) or nitrogen

Question 16

In cooking how does the texture of egg (for example) change?

Answer 16

Molecules become agitated and more around causing intermolecular bonds to break (these are hydrogen bonds)
Protein then DENATURES

Question 17

What causes the protein to denature?

Answer 17

Temperature

Question 18

Describe the attributes of amino acids in terms of being hydrophilic or hydrophobic
Stare the dissolving rule that can be applied here

Answer 18

Some amino acids have polar, HYDROPHILIC side chains
Others have non-polar, HYDROPHOBIC side chains
LIKE DISSOLVES LIKE

Question 19

Give an example of a hydrophilic and hydrophobic side chain

Answer 19

-Philic -OH and -COH polar
nonpolsr /
-Phobic -CH3 -CH2-C-HCH2