biological molecules

Question 1

what number carbons connect to make maltose?

Answer 1

1,4

Question 2

what type of glucose makes starch?

Answer 2

alpha

Question 3

is amylose or amylopectin branched

Answer 3

amylopectin

Question 4

why is amylopectin good for storage?

Answer 4

structure makes it compact, insoluble so doesn’t affect water potential

Question 5

which cell structures contain starch?

Answer 5

amyloplasts

Question 6

which glucose is found in cellulose?

Answer 6

beta

Question 7

what number bonds join glucose in cellulose?

Answer 7

1,4

Question 8

how is glucose arranged in cellulose

Answer 8

every other molecule is flipped 180°

Question 9

what are bacteria cells made of

Answer 9

peptidoglycan

Question 10

what is a microfibril

Answer 10

a group of many cellulose chains

Question 11

what is a property of cellulose

Answer 11

tensile strength

Question 12

where is glycogen stored in animals?

Answer 12

liver and muscle

Question 13

what is the structure of glycogen?

Answer 13

branched

Question 14

what is used for the reducing sugars test

Answer 14

benedict’s

Question 15

what colour shows a reducing sugar?

Answer 15

brick red

Question 16

where are amino acids joined together?

Answer 16

by their carboxyl and amino groups

Question 17

where are secondary and tertiary structures folded?

Answer 17

in the rough ER

Question 18

which R groups are arranged outside of a globular protein?

Answer 18

hydrophilic

Question 19

2 examples of globular proteins

Answer 19

haemoglobin and enzymes

Question 20

what protein structure does collagen have?

Answer 20

quaternary

Question 21

what are proteins with prosthetic groups called?

Answer 21

conjugated proteins

Question 22

what is used to test for proteins?

Answer 22

biurets

Question 23

what shows a positive result for proteins

Answer 23

lilac

Question 24

why is it important that ice floats on water?

Answer 24

creates insulation

Question 25

what would happen to organisms in water that was over 45°?

Answer 25

their enzymes would denature

Question 26

why does it take so much energy to raise water temperature?

Answer 26

many hydrogen bonds to break so they can gain kinetic energy

Question 27

why does water need a stable temperature?

Answer 27

enzymes are very sensitive to temperature change

Question 28

why is it an advantage that water is polar?

Answer 28

can dissolve other polar molecules making it a good transport medium

Question 29

how does adhesion and cohesion support water in the xylem?

Answer 29

cohesion keeps a continuous stream of water, adhesion stops water travelling back down the xylem

Question 30

which type of fatty acids have carbon double bonds?

Answer 30

unsaturated

Question 31

which fatty acid have a lower melting point?

Answer 31

unsaturated

Question 32

how can water pass a plasma membrane

Answer 32

inbetween bilayer or facilitated diffusion

Question 33

why can’t sodium and potassium ions pass through the bilayer?

Answer 33

they’re charged

Question 34

what is the role of magnesium ions in plants?

Answer 34

to make chlorophyll

Question 35

two uses of phosphate in cells

Answer 35

to make nucleic acids and atp

Question 36

what is the role of the phospholipid bilayer in membranes?

Answer 36

to prevent entry of water soluble substances

Question 37

what is the role of glycoproteins

Answer 37

cell signalling and recognition

Question 38

what role do calcium ions play in plants and animals

Answer 38

blood clotting, muscle contractions and the middle lamella for plant division

Question 39

does water move towards a pure or impure solution?

Answer 39

impure

Question 40

what happens to plant cells in low water potentials?

Answer 40

plasmolysis - shrinks

Question 41

explain the difference between ribose and deoxyribose

Answer 41

deoxyribose has no oxygen on c2

Question 42

how many water molecules are produced when a nucleotide forms?

Answer 42

two

Question 43

what bond connects nucleotides

Answer 43

phosphodiester

Question 44

what reaction joins nucleotides

Answer 44

condensation

Question 45

3 differences between DNA and RNA

Answer 45

dna is double stranded, has thymine and deoxyribose rna is single stranded, has uracil and ribose

Question 46

how many H bonds form between GC and AT

Answer 46

GC - triple h AT - double h

Question 47

role of dna helicase

Answer 47

breaks h binds to unzip dna strands

Question 48

role of dna polymerase

Answer 48

attracts free dna nucleotides and forms phosphodiester bonds, checks for errors

Question 49

role of dna ligase

Answer 49

joins the dna fragments on the lagging strand to form a phosphodiester backbone

Question 50

why is dna replication necessary?

Answer 50

for mitosis

Question 51

which strand acts as a template for protein synthesis

Answer 51

antisense

Question 52

what’s the structure of mRNA?

Answer 52

single stranded, A U G C, smaller than DNA

Question 53

what’s the structure of tRNA?

Answer 53

single stranded, clover leaf shape held by h bonds, one end has the amino acid binding site, the other has the anti codon loop where it pairs with mRNA codons

Question 54

how are amino acids activated?

Answer 54

it binds to tRNA binding site

Question 55

what’s the difference between introns and exons?

Answer 55

introns are non coding, exons are coding

Question 56

when does editing occur in protein synthesis

Answer 56

between transcription and translation to create mRNA from pre mRNA

Question 57

how can splicing created different polypeptides from the same gene?

Answer 57

exons can be rearranged in many orders to creat slightly different proteins

Question 58

what is a mutagen

Answer 58

something that can cause mutations in DNA (e.g radiation)

Question 59

structure of enzymes

Answer 59

- globular proteins - active site - hydrophilic r groups outside and have many small r groups

Question 60

saturated vs unsaturated fats

Answer 60

saturated - no double bonds between individual carbons unsaturated- at least one double bond in the chain

Question 61

how to identify a lipid

Answer 61

fatty acids have a carboxyl group cooh

Question 62

what are the two types of cholesterol

Answer 62

LDLs (low density liposuction) - increase risk of heart disease/atherosclerosis HDLs (high d) - transports LDLs to liver to be broken down

Question 63

why are triglycerides good for storage

Answer 63

- store more energy per gram (than proteins/carbs) - high carbon + hydrogen content - contains no water

Question 64

how are triglycerides formed

Answer 64

- esterification - when OH from glycerol bonds with COOH of fatty acid - each bond formed releases one H2O - leaving COO

Question 65

formula for ribose

Answer 65

C5 H10 O5

Question 66

comparing hds and ldls

Answer 66

- hdls are smaller, can be stored - ldls stay in bloodstream - hdls have more protein

Question 67

translation process

Answer 67

- ribosome attached to mrna start codon with specific amino acid - moved to next codon - 2 at a time and attaches - ribosome catalyses condensation between aminos and joins with peptide bond - forms polypeptide until stop codon, unattaches and leaves

Question 68

sickle cell anaemia

Answer 68

valine replaced by glu

Question 69

sickle cell anemia

Answer 69

- point mutation valine to glutamic acid - haemoglobin is inverted, carries less 02 - can block vessels and cause pain and swelling