biology 1 : biological molecules - proteins and lipids

Question 1

what are lipids used for and where are they found

Answer 1

source a energy
oils and fats
waterproofing
reduce heat loss

Question 2

triglycerides structure

Answer 2

1 glycerol with 3 fatty acids

Question 3

what do fatty acids contain

Answer 3

carboxylic group

Question 4

what does a molecule of gylcerol contains

Answer 4

3 hydroxyl

Question 5

what happens when fatty acids and glycerrol react

Answer 5

form an ester bond

Question 6

name the properties of trigylcerides

Answer 6

non polar - hydrophoic
contains alot of carbon and hydrogen so a lot of energy can be released

Question 7

what is the structure of a phospholipid

Answer 7

phosphate head glycerol + 2 fatty acids

Question 8

What is the difference between the head and the tail of a phospholipid

Answer 8

polar head
non polar tail

Question 9

what is the structure of a amino acid

Answer 9

amine group(NH2)
carboxyl(cooh)
r group

Question 10

whats is the bond called when amino acids react

Answer 10

peptide bonds

Question 11

what happens when you join mant amino acids

Answer 11

polypeptide

Question 12

whats the difference between a polypeptide and a protein

Answer 12

need to fold into a complex 3d shape

Question 13

what is the primary structure

Answer 13

specific order of amino acids in a polypeptide(helps determine the final 3d structure)

Question 14

what causes the secondary structure

Answer 14

nh groups are slightly positive
co groups are slightly negative
they will attract each other and form hydrogen bonds
which causes it to twist into the secondary structure (alpha helix or beta pleated sheets)

Question 15

what causes the teritary structure

Answer 15

beat pleated sheet and alpha helix being folded

Question 16

what causes the formation of the quaternary structure

Answer 16

many polypeptides(subunits) working together
to form a larger 3d structure

Question 17

what is it called when non protein molecules are formed at the quarternary structure

Answer 17

prosthetic groups
e.g(heam helps oxygen to bind)

Question 18

what occurs during hydrogen bonding (hydroxyl)

Answer 18

due to a slight positive and negative charge on the hydroxyl
hydrogen bon will form
contributes the 3d shape of polypeptide chain
weak bonds

Question 19

how does ionic bonding occur in proteins

Answer 19

between amino acids with charged r groups
r groups that are oppositely charged attract with each other
and form ionic bonds
only broken by changes in ph (reason why enzymes denature)

Question 20

how does disulfide bonding occur

Answer 20

two molecules of cysteine(amino acids)
this contains a sulfur atom
sulfur atoms form a covalent bond

Question 21

how can ionic bonds in proteins be broken

Answer 21

only broken by changes in ph (reason why enzymes denature)

Question 22

how can disulfide bond be broken

Answer 22

they cant be broken down with temperature or ph
very strong

Question 23

how do we know which bonds are in the tertiary structure

Answer 23

if they form between polypeptides on the same chain

Question 24

how do we know which bonds are in the quaternary structure

Answer 24

if they form between different sub units

Question 25

explain the induced fit model

Answer 25

complementary substrate causes
the tertiary structure of the active site to mould itself around the substrate(bonds are formed with amino acids)
(bonds formed help catalyse the reaction)
enzyme-substrate complex formed

Question 26

what happens in noncompetitive inhibition

Answer 26

bind to the allosteric site
causes tertiary structure to change(changes active site)
substrate no longer fits
(can not be overcome)

Question 27

what happens in competitive inhibition

Answer 27

comeplementay to substrate
binds to active site
however its not permanent
increasing substate concentration reduces affect of it

Question 28

name 6 ways that affect the rate of reaction

Answer 28

enzyme concentration
substate concentration
non competititve
competitive inhibitors
ph
temperature

Question 29

How do you join two amino acids together

Answer 29

(H) in amine group bonds to (oh) in carboxyl group

Question 30

Name all the bonds that make up the tertiary structure and it’s backbone

Answer 30

Disulfide
Ionic
Hydrogen
Backbone= polypeptide