Biological Mpleculws 1

Question 1

Name some monosaccarides

Answer 1

Glucose Galactose and fructose

Question 2

How does the structure of glucose relate to its function

Answer 2

Small and water soluble so easily transported I’m the bloodstream
Complementary shape to the antip for co transport for absorption in the gut
Complementary shape to enzymes for glycolysis

Question 3

How is the strcytyre of glycogen suitable for its function

Answer 3

Long chain of alpha glucose molecules joined by 1,4 glucoside bonds. It is an energy store in animals. Due to having many side branches it can be broken down to release glucose. It Is also large but compact due to the coiling nature of its polymer chain

Question 4

Why light an animal not be able to digest cellulose

Answer 4

Due to it not containing the enzymes to digest the 1,4 glucoside bonds between beta glucose molecules. It may he hard to hydrole because it is a polysaccaride

Question 5

Why are lipids good at storing energy

Answer 5

Because it is insoluble and non polar so it does not interfere with any water based reactions taking place in the cytoplasm

Question 6

What is the function of phospholipid bilayer

Answer 6

Forms a partially permeable membrane. It only allows certain substances to pass through for example oxygen and carbon dioxide
Keeps the membrane fluid but stable
The tail prevents unwanted polar ions and molecules to pass in the cell and prevents water soluble molecules like amino acid and glucose from entering
Only small non polr molecules can enter

Question 7

What affects the fluidity of the cell membrane

Answer 7

Length of the fatty acid chain: the shorter the chain
Saturation of fatty acid: more unsaturated the more fluid due to it creating a kink which makes them fit more loosely
Cholestrol

Question 8

How does a polypeptide form

Answer 8

Chains of amino acid linked together by condensation recations. This occurs as a part of protein synthesis called translation. During condensation, a peptide bond forms between he amine groups nd the carboxylic group of another amino acid and water is produced

Question 9

How do proteins form?

Answer 9

Many amino acids joined together by peptide bonds

Question 10

Structure of proteins 1-4

Answer 10

Primary
Secondary
Tertiary
Quarternery

Question 11

Primary

Answer 11

Sequence of amino acids within a polypeptide chain joined together by peptide bonds

Question 12

Secondary

Answer 12

Folding of the polypeptide chain into alphabheoices or beta pleated held together by hydrogen bonds and due to formation of hydrogen bonds

Question 13

Tertairy

Answer 13

The 3 dimensional folding of the secondary structure into a complex shape determined by the type of bondin
H
I
D
Determined by the folding of an alpha or beta pleated sheet folding caused by interactions between r groups of amino acids

Question 14

Why do alpha helices and beta pleated form

Answer 14

Due to structure of amino acids

Question 15

Quaternary strcuture

Answer 15

3D arrangement of more than one polypeptide

Question 16

Fibrous protein

Answer 16

Include collagen
Long parallel polypeptide
Very little teriaru or quaternary structure mainly secondary
Occasional cross linkages which form microfibrils for strength
Insoluble
Structural purposes

Question 17

Globular

Answer 17

U

Question 18

Globular proteins

Answer 18

Complex teriary quaternary structure
Form colloids in water
Includes haemoglobin 
Spherical in shape
Hydrophobic R groups on the inside
Hydrophilic r groups on the outside
Soluble in water anything soluble makes bond with the water
Specific shape to carry out specific functions

Question 19

Role of globular proteins

Answer 19

Transport
Hormones
Enzymes
Metabolic roles
Holding molecules in position in cytoplasm
Immune system producing antibodies which are globular proteins
Maintain strcutyr of cytoplams

Question 20

How does the structure of collagen relate to their function

Answer 20

Fibrous proteins that give strength to bones and tendons and ligaments
Structural protein
Strong due to fibres having high tensile strength due to structure of collagen
3 polypeptide chains of repeating glyceine, proline and hydroxyproline.
3 alpha chains arranged in triple helix held together by hydrogen bonds
Glycerine held close together to form triple helix
Covalent bonds forming cross links holding collagen molecules together to form fibrils
Hydrogen bonds= withstand pulling forces without stretching or breaking
Stable protein due to Hugh number of proline and hydroxyproline amino acids resulting in more stability as their R groups repel each other.

Question 21

How does the structure of hamoglobin relate to their function

Answer 21

4 polypeptide chains held together by disulfide bonds each carrying a haem group which can bind to oxygen
Large molecule
Iron containing haem group
It is the iron that enable the haemoglobin haemoglobin bind to oxygen and polypeptide chains that determine how easy it is to bind or release oxygen

Question 22

G

Answer 22

G

Question 23

Compare collagen with heamoglobin

Answer 23

Collagen
Triple helix
Long 
Fibrous
Haemoglobin
4 2 alpha 2 globin trands 
Spherical
Globular