B1.2

Question 1

gene

Answer 1

section of DNA giving the instructions for a cell about how to make one kind of protein

Question 2

chromosome

Answer 2

long structures in the nucleus made from a molecule of DNA

Question 3

nucleus

Answer 3

the part of a eukaryotic cell that contains genes and controls the cells activities

Question 4

DNA

Answer 4

biological polymer made from nucleotide monomers, contains all genetic material of an organism

Question 5

polymer

Answer 5

large molecule composed of multiple repeating units

Question 6

monomer

Answer 6

molecule that can be bonded to other identical molecules to form a polymer

Question 7

what is DNA and what is it made from?

Answer 7

DNA is a polymer and is made from repeated units called nucleotides

Question 8

nucleotide structure

Answer 8

(circle)- phosphate
(pentagon)- sugar
(rectangle- nitrogenous base

Question 9

structure of DNA

Answer 9

-made of two polynucleotide chain which are held together by hydrogen bonds
-they form a double helix

Question 10

complimentary base pairing

Answer 10

adenine-thymine (2 hydrogen bonds)
cytosine-guanine (3 hydrogen bonds)

Question 11

what are proteins made of?

Answer 11

long chains of amino acids

Question 12

what is catalase?

Answer 12

an enzyme found in every cell

Question 13

what are chromosomes made of?

Answer 13

genes

Question 14

why do we have pairs of chromosomes?

Answer 14

each parent contributes a chromosome

Question 15

what does one gene code for?

Answer 15

proteins

Question 16

what is an allele?

Answer 16

different versions of the same gene

Question 17

how many chromosomes do humans have?

Answer 17

46

Question 18

what number pair of chromosomes are the sex chromosomes?

Answer 18

23rd

Question 19

describe the shape of a helix

Answer 19

a coil

Question 20

what is meant by the term complimentary base pairing?

Answer 20

the arrangement of bases in relation to their opposite pairing

Question 21

why is a sequence of 3 bases on a DNA strand referred to as a triplet code?

Answer 21

more than three times the number of codons than amino acids

Question 22

name for the molecule that an enzyme is acting on

Answer 22

substrate

Question 23

described as a protein and a biological catalyst

Answer 23

enzyme

Question 24

name given to the temperature that the enzyme works the fastest at

Answer 24

optimum temperature

Question 25

optimum temperature of enzymes in the human body

Answer 25

37°C

Question 26

the scientific word to explain that an enzyme is no longer functional

Answer 26

denatured

Question 27

the name given to the model that explains how an enzyme works

Answer 27

the lock and key model

Question 28

when an enzyme docks into a substrate what is produced

Answer 28

product

Question 29

the region on the enzyme that binds to the substrate and has a very specific shape

Answer 29

active site

Question 30

factors that affect the rate of enzyme controlled reactions

Answer 30

temperature, pH, substrate concentration and enzyme concentration

Question 31

carbohydrase is an enzyme that breaks down...

Answer 31

carbohydrates

Question 32

protease is an enzyme that breaks down...

Answer 32

proteins

Question 33

lipase is an enzyme that breaks down...

Answer 33

fats

Question 34

amylase is an enzyme that breaks down...

Answer 34

starch

Question 35

amylase is an enzyme which breaks down large carbohydrate molecules. explain why it is unable to break down proteins

Answer 35

-enzymes only act on one substrate, they are highly specific -the shape of the active site is complimentary to the shape of the substrate -reference to the lock and key hypothesis -the shape of the active site of amylase is not complimentary to the shape of protein -an enzyme substrate complex cannot form and the reaction cannot be catalysed

Question 36

collision theory

Answer 36

-the particles must have enough kinetic energy to collide with the reactant and produce products in the reaction -the rate of reaction depends on the rate of successful collisions between particles

Question 37

fresh liver

Answer 37

-bubbles of oxygen gas as the catalase enzyme breaks down the hydrogen peroxide -the shape of the active sit is complimentary to the shape of hydrogen peroxide, catalyzing the reaction

Question 38

boiled liver

Answer 38

-no reaction took place -high temperatures denatured catalase, changing the shape of the active site, preventing enzyme substrate complexes from being formed

Question 39

apple without acid

Answer 39

-rapid browning of the apple -the active site shape of phenolase is complimentary to the shape of the substrate, catalyzing the reaction

Question 40

apple with acid

Answer 40

-apple did not brown -the acid lowers the pH of the environment, denatures the active site, preventing a reaction

Question 41

what do enzymes do?

Answer 41

speed up reactions

Question 42

enzyme controlled reactions

Answer 42

-metabolic reactions -respiration -photosynthesis

Question 43

rate of reaction temperature graph

Answer 43

-at low temperatures the rate of reaction starts to increase as temperatures increase. the enzymes have more kinetic energy and form more collisions with the substrate -at the optimum temperature is the quickest rate of reaction where the most collisions take place -at high temperatures the enzymes start the denature, the active site has changed shape, slowing the rate of reaction, after 60C all enzymes have denatured

Question 44

rate of reaction pH graph

Answer 44

-outside the pH range there is no rate of reaction, enzymes would denature -at the optimum pH is the quickest rate of reaction for the enzyme, more collisions occuring -at either side of the optimum pH the enzymes start to denature, the active sit changes shape

Question 45

rate of reaction substrate concentration graph

Answer 45

-at a certain concentration all the enzyme molecules are bound to substrate molecules -no more enzymes are available for the substrate to bind to and so increasing the substrate concentration past this point does not have any effect on the rate of reaction

Question 46

rate of reaction enzyme concentration graph

Answer 46

-increasing the enzyme concentration will speed up the rate of reaction, until there are no more substrates to break down/up -this will stop the reaction alltogether