Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

OCR Biology > Biological molecules > Flashcards

Biological molecules Flashcards

You may prefer our related Brainscape-certified flashcards:
AP® Biology flashcards Biology 101 flashcards
1
Q

what role do calcium ions play? Ca2+

A

involved in muscle contraction and nerve impulse transmission

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what role do sodium ions play? Na+

A

involved in co-transport, reabsorption of water in the kidney and nerves impulse transmission

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what role do potassium ions play? K+

A

involved in stomatal opening and nerve impulses transmission

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what role do hydrogen ions play? H+

A

involved in chemioamosis, pH determination and catalysis of reactions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what role do nitrate ions play ? NO3-

A

mineral ion absorbed by plants to provide a source of nitrogen to make aminonacids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what role does the hydrogencarbonate play? HCO3-

A

maintains the pH of the blood

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what role do the phosphate ions play? PO4 3-

A

involved in the formation of phospholipids for cell membranes, nucleic acids and ATP formation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

describe the structure of a water molecules

A

one atom of oxygen
two atoms oh hydrogen
covalently bonded

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what makes water polar?

A

it has a partially negative charge on the oxygen and a partially positve charge on the hydrogen, this is due to the uneven distribution of the shared pair of electrons in the covalent bond.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what is hydrogen bonding?

A

it is when the partial negative charge on an oxygen attract the partial positive charge on a neighbouring hydrogen atom

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what are the 4 key properties of water?

A

1- as a solvent in reactions
2- a transport medium
3- as a coolant
4- provides habitat

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

why is water a good solvent?

A

polar (hydrophilic) or charged molecules dissolve readily in water due to the fact water is polar.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

How do hydrogen bonds give water a high specific heat capacity?

A

The hydrogen bonds between water molecules can absorb a lot of energy, so it takes a lot of energy to heat up the water and overcome the bonds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

How does having a high specific heat capacity make water a good habitat?

A

It means that the water does not experience rapid temperature changes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Why does water have a high latent heat of evaporation?

A

It takes a lot of energy to break the hydrogen bonds between water molecules, so a lot of energy is used up when it evaporates

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Why is it useful that water has a high latent heat of evaporation for living organisms?

A

It means that water is great for cooling things, for example, some mammals sweat when they are hot to cool the surface of the skin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is cohesion?

A

The attraction between molecules of the same type. eg in water, molecules stick to each other by hydrogen bonds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What are the advantages of water being cohesive?

A

It helps water flow, making it great for transporting substances
It helps water be transported up plant stems in the transpiration stream

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Why is it useful that ice floats on water?

A

In cold temperatures, ice forms an insulating layer on top of water and so the water below does not freeze.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Why is water less dense as a solid than a liquid?

A

Water molecules are held further apart in ice than they are in water because each water molecule forms four hydrogen bonds to other water molecules, making a lattice shape

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

how does cohesion provide habitat?

A

the cohesion provides surface tension to water. this enable small invertebrates to move and live on the surface, providing them a habitat.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

give three hexose monosaccharides

A

glucose, fructose and galactose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What are the monomers that make up carbohydrates?

A

monosaccharides

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is the difference between alpha and beta glucose?

A

Alpha glucose hydroxyl group on c1 is below the plane
Beta glucose hydroxyl group on c1 is above the plane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

name two pentose monosaccharides

A

ribose and deoxyribose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

How do monosaccharides join together?

A

glycosidic bonds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What is a condensation reaction?

A

a hydrogen atom on one monosaccharide bonds to an OH group on the other, releasing a molecule of water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What is a hydrolysis reaction?

A

When a molecule of water reacts with the glycosidic bond, breaking it apart

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

what is a disaccharide

A

two monosaccharides joined together by a glycosidic bond in a condensation reaction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

How is maltose formed?

A

alpha glucose + alpha glucose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

how is lactose formed?

A

alpha glucose + galactose

31
Q

How is sucrose formed?

A

alpha glucose + fructose

32
Q

what is a polysaccharide?

A

When more than two monosaccharides are joined together glycosidic bonds by condensation reactions

33
Q

What do plants store excess glucose as?

A

starch - it is insoluble in water, so does not affect water potential

34
Q

What is the function of starch?

A

it is the main energy storage material in plants

35
Q

What two polysaccharides make up starch?

A

amylose and amylopectin

36
Q

Describe amylose

A

A long unbranched chain of alpha glucose
Coiled structure
Compact - good for storage
Joined by 1-4 glycosidic bonds

37
Q

describe amylopectin

A

Made by 1-4 glycosidic bonds
Some 1-6 glycosidic bonds
Branched structure
Very compact
Free ends where glucose can be added or removed
Insoluble

38
Q

What bonds form between two glucose molecules?

A

alpha 1-4 glycosidic bonds

38
Q

what is glycogen?

A

it is the main energy storage material in animals.
animals store excess glucose and glycogen- another polysaccharide of glucose

39
Q

describe glycogen

A

its structure is very highly branched , has loads of side branches means that stored glucose can be released quickly via hydrolysis . it is very compact

40
Q

What molecules make up cellulose

A

Beta glucose molecules

41
Q

How do beta glucose molecules join together?

A

They join by 1-4 glycosidic bonds
Every other molecules is flipped 180 degrees

42
Q

describe cellulose

A

long, unbranched chains of beta glucose. these chains are held in parallel by many hydrogen bonds to form fibrils. macrofibrils combine to form cellulose fibres. Many hydrogen bonds provide collective strength. It is also insoluble- wont affect water potential

43
Q

what are the three types of lipids?

A

triglycerides
phospholipids
cholesterol

44
Q

What are triglycerides composed of?

A

1 glycerol and 3 fatty acids

45
Q

what are the two types of fatty acid

A

saturated or unsaturated

46
Q

how are triglycerides formed?

A

via a condensation reaction (esterification) between one molecule of glycerol and three molecules of fatty acid, forming three ester bonds

47
Q

what are saturated fatty acids

A

they dont have any double bonds between their carbon atoms. the fatty acid is saturated with hydrogen

48
Q

what are the key properties of triglycerides

A

1- long hydrocarbon tails of fatty acids contain lots of chemical energy - lots of energy is released when they are broken down
2- act as metabolic water source, triglycerides can release water if oxidised, essential for animals in desert such as camels
3- as lipids are large hydrophobic molecules they are insoluble in water. this means they will not affect the water potential

49
Q

what are unsaturated fatty acids

A

unsaturated fatty acids had at least one double bond between carbon atoms, which cause the chain to kink

50
Q

What are the functions of triglycerides in the body?

A

Triglycerides serve as a source of energy for the body. They are stored in adipose tissue and can be broken down to release energy when needed. Triglycerides also help to insulate the body and protect vital organs.

51
Q

what are phospholipids made of

A

a glycerol with a phosphate group attached and two fatty acid chains (one chain is saturated, one is unsaturated)

52
Q

how are phospholipids made

A

the two fatty acids also bond to the glycerol via condensation reactions to form two ester bonds

53
Q

why are phospholipids amphipathic

A

they have both hydrophobic (repelled from water) tails and hydrophilic (attracted to water) head, due to the phosphate group

54
Q

How do phospholipids form the structure of cell membranes?

A

Phospholipids form the structure of cell membranes by arranging themselves in a double layer, or bilayer, with the hydrophobic tails facing inward and the hydrophilic heads facing outward. This arrangement allows the cell membrane to control the flow of substances in and out of the cell while also maintaining the integrity of the cell.

55
Q

What is the significance of the hydrophobic and hydrophilic properties of phospholipids?

A

The hydrophobic and hydrophilic properties of phospholipids are significant because they allow the formation of the cell membrane bilayer. The hydrophobic tails are able to interact with each other, creating a barrier that separates the inside of the cell from the outside environment. The hydrophilic heads, on the other hand, allow for the exchange of substances between the cell and its environment, as well as for communication between cells.

56
Q

what is a micelle

A

is a singe layer of phospholipids with tails pointing inwards eg vesicles and lysosomes

57
Q

what is a cholesterol

A

it is a sterol, has 4 carbon rings and a hydroxyl group at one end, it has both hydrophobic and hydrophilic (hydroxyl end) regions

58
Q

why is cholesterol important in membranes

A

1- small size and flattened shape means it can fit between the phospholipid molecules in the membrane
2- at high temps, they bind to the hydrophobic tails of the phospholipids, causing them to pack more closely. this helps the membrane be less fluid and more rigid
3- at lower temperature cholesterol prevents phospholipids from packing too close, so increases the fluidity

58
Q

What are the monomers of proteins?

A

amino acids

59
Q

What is a dipeptide?

A

2 amino acids

60
Q

what is a polypeptide

A

more than 2 amino acids joined together

61
Q

Describe the structure of an amino acid

A

A carboxyl group
an amine group attached to a carbon atom
a single hydrogen
A variable R group
Image: Describe the structure of an amino acid

62
Q

How do amino acids join together?

A

peptide bonds (condensation reaction)

63
Q

Describe the primary structure of a protein

A

sequence of amino acids in a polypeptide chain
held together by peptide bonds

64
Q

Describe the secondary structure of a protein

A

Hydrogen bonds form between amino acids in the chain
Folds into beta pleated sheet or coils into an alpha helix

65
Q

describe the tertiary structure of a protein

A

the secondary structure is furhter bent and folded to form a precise 3D shape
bonds that hold it:
- hydrophobic and philic interactions
- more hydrogen bonds
- ionic bonds (- & + charged r groups)
- disulfide bonds (covalent between cysteine)

66
Q

name three globular proteins

A

haemoglobin, insulin and amylase

66
Q

describe the quaternary structure

A

proteins made from more than one polypeptide chain held together by bonds

67
Q

describe haemoglobins structure

A
  • it is made of four polypeptide chains
  • it is a conjugated protein as it has a non-protein group attached, called the prosthetic group
  • each of the 4 chains has a prosthetic group called haem
  • a haem group contains iron, which oxygen binds to
68
Q

what are globular proteins

A
  • polypeptide chains rolled into spherical shape
  • soluble
  • metabolic functions
  • eg enzymes, antibodies, hormones
69
Q

name three fibrous proteins

A

collagen, keratin and elastin

70
Q

what are fibrous proteins

A
  • long parallel polypeptide chains
  • cross linkages forming long fibres/sheets
  • insoluble
  • have many structural roles
71
Q

where is collagen found

A

skin tendons, cartilage, bones and teeth

72
Q

where is keratin found

A

found in hairs, skin and nails, has high proportion of cysteine

OCR Biology (14 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions