Brainscape's Knowledge GenomeTM

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


See full index

Biology > Biological Molecules:2:2 > Flashcards

Biological Molecules:2:2 Flashcards

1
Q

What elements do carbohydrates contain?

A

Carbon, hydrogen and oxygen

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

What is monosaccharides ?

A

Single sugar monomers.They are the simplest carbohydrates.

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

What are the functions of carbohydrates ?

A

They act as a source of energy ,
As a store of energy,
And as structural units

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

What is a disaccharide ?

A

Two monosaccharides join together

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

What is a polysaccharide?

A

Many monosaccharides join together.

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

Properties of monosaccharides

A

Soluble and sweet so know as Sugars

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

Commonly found hexose monosaccharides

A

Glucose, fructose,galactose

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

Properties of glucose

A

Main source of energy in respiration

It is used as building blocks for larger carbohydrates

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

Structure of glucose that make it well adapted for its role

A

Small so easily transported in and out of cells through carrier proteins.

Soluable so easily transported around an organism e.g in the blood stream. This is because it contains are large number of OH groups called hydroxyl groups which can form hydrogen bonds with water molecules making them soluable in water. They are hydrophilic.

Less reactive than other monosaccharides so breakdown must be catalysed and therefore controlled by enzymes.e.g rate of respiration can be controlled

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

Isomers of glucose

A

A-glucose(alpha) and b- glucose (beta)

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

What are the monomers in proteins called

A

Amino acid

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

What is the polymers in proteins called

A

Polypeptide

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

What are monomers called in nucleic acids

A

Nucleotides

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

How do we form maltose ?

A

A- glucose + a- glucose

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

How is sucrose formed ?

A

A- glucose + fructose

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

How is lactose formed ?

A

B-glucose + galactose

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

How do we form maltose ?

A

A- glucose + a- glucose

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

How is sucrose formed ?

A

A- glucose + fructose

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

How is lactose formed ?

A

B-glucose + galactose

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

How is polysaccharides used as an energy store ?

A

a- glucose is the main use of energy in respiration as it is used to make ATP. When we have too much glucose excess chemical energy is stored in the cells by forming polysaccharides of a-glucose. Plants store energy as starch in chloroplast and humans store energy as glycogen in cells of the muscle and liver.

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

Why are polysaccharides good energy stores ?

A
  • they are compact so a lot of energy can be stored in a small space.
  • they are insoluble in water so do not impact the water potential of the cell therefore stopping cytolysis from happening
  • they are large so they don’t diffuse in and out of the cell
  • can be easily be hydrolysed to a-glucose when energy is needed. Enzymes assess the end of the polysaccharides and can break them by ‘snipping the chains off’
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Properties of polysaccharides

A
  • Large molecule
  • insoluble molecule
  • compact
  • easily broken down
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is polysaccaride amylose? ( in plants)

A
  • a long chain of a-glucose molecules.
    -It has glycosidic bonds between carbons 1 and 4 like maltose.
  • It could into a spiral shape which are held together by hydrogen bonds. The hydroxyl groups on carbon 2 are situated on the inside of the coil making it less soluble and allowing hydrogen bonds to form to maintain the coils structure.
24
Q

What is amylopectin? (In plants)

A

Has glycosidic bonds between carbons 1 and 4 but in addition has branches formed by glycosidic bonds between carbon 1 and 6.
- It coils into a spiral shape with hydrogen bonds holding it together but with branches emerging from the spiral.

25
Q

What is the polysaccharides glycogen (in animals)?

A

Has glycosidic bonds between carbon 1 and 4, and branches formed by glycosidic bonds between carbon 1 and 6. The 1-4 bonded chains tend to be smaller than in amylopectin so glycogen has less tendency to coil. But it has more branches, which makes it more compact and easier to remove monomer units as there is more branches

26
Q

What is cellulose ?

A

Found in plants. High tensile strength so stop the cell wall bursting when to much water is entered so is turgid.

27
Q

What is cellulose made up from ?

A

B-glucose molecules joined together by 1,4 glycosidic bonds.

28
Q

How is cellulose formed

A
  • because on carbon 1 OH group are inverted
  • every other B -glucose molecule is rotated by 180 degrees
  • this therefore prevents the chain from spiralling creating a long chain
  • forms cross links via hydrogen bonds to adjacent chains as the OH group on carbon 2 sticks out giving cellulose additional strength
29
Q

What features of cellulose allow the plant cell walls to do its job ?

A
  • cell wall fully permeable to allow water and mineral ions to pass through
  • the wall has high tensile strength preventing the cell from bursting.
  • do not have a rigid skeleton so supports the whole plant
  • difficult to digest due to the glycosidic bond and most animals do it have enzymes (cellulase) to catalyse the reaction
30
Q

What are bacteria cell walls made of ?

A
  • peptidoglycan
31
Q

How do we test for starch ?

A

add iodine If starch is present the iodine solution turns from yellow-brown to blue-black

32
Q

How do we test for proteins ?

A
  • A biuret test . If protein is present then the colour of reagent will go from light blue to lilac.
33
Q

How do we test for lipids?

A
  • emulsion test
  • add a few drops of ethanol
    -shake
    -pour over water
  • if lipids are present you will get a white emulsion
34
Q

Define a reducing sugar?

A

Reducing sugars can donate an electron to another molecule
- glucose
-lactose
-galactose
-fructose

35
Q

How do we test for reducing sugars?

A
  • Heat the sample with Benedict solution in a water bath
  • if reducing sugar is present yellow/green/orange/brick red colour appears

OR
-reagent test strips

36
Q

How do we test for non-reducing sugars ? E.g. sucrose

A
  • heat sample with Benedict’s
  • if no change then heat with acid/HCL
  • add excess NaOH
  • heat sample with Benedict’s
  • Non-reducing sugar present if a yellow/green/orange/brick red colour appears
37
Q

What are the two main types of lipids ?

A

Triglycerides and phospholipids

38
Q

Function of triglycerides? (7)

A
  • Buoyancy
  • form layers of insulation for warmth or protective layer around organs or nerves e.g myelin sheath
    -waterproofing as oil repels water
    -used to make hormones
  • used as a respiratory substrate; they release water when broken down
  • insoluble so dont affect water potential so can store water
39
Q

Function of phospholipids?

A
  • for a phospholipid bilayer
    Because..
  • the fatty acids are non- polar and insoluble in water (hydrophobic) so orientate away from water
  • the phosphate group is polar and soluabe in water ( hydrophilic) and orientate towrards water
40
Q

What is meant by primary structure?

A
  • the sequence of amino acids bonded by peptide bonds
41
Q

Define secondary structure

A

The folding of polypeptide chains held in place with hydrogen bonds; Alpha helix or Beta pleated sheets

42
Q

What is tertiary structure ?

A
  • further folding of polypeptide chains
  • held in place with hydrogen bonds, disulphide brides, ionic bonds,
    Hydrophobic and hydrophilic interactions
  • amino acids with hydrophobic R groups orientate forwards the center of the protein; amino acids with hydrophilic R groups orientate towards the outside of the protein
43
Q

Define quartennary structure ?

A
  • more than one polypeptide chain
44
Q

What are globular proteins?

A
  • a protein with a 3D spherical
    -soluble in water.
  • they are compact
  • conjugated proteins= globular proteins with a prosthetic group for example haemoglobin
45
Q

Example of globular proteins

A
  • insulin- specific fixed shape
  • haemoglobin( conjugated protein)- can change shape
    -catalase( conjugated protein)- specific fixed shape
46
Q

What are fiborous proteins?

A
  • a very strong and insoluable protien which often has structural roles in organism
47
Q

Example of fiborous proteins

A

-keratin- hair and nail strength
-Elastin( alveoli)- recoils after being deformed
-collagen(skin)- flexible but doesn’t stretch

48
Q

How do we use a colorimeter to determine the concentration of substance

A

-make a series’s dilution
-test for reducing sugars using Benedict’s solution
-use the same volume of Benedict’s and the same volume of sugar, treat unknown the same
- filter out the preticipate
- calibrate the colorimeter by setting it to zero using a blank
- use a red filter
-measure the absorbable
- plot a calibration curve and find the concentration of unknown sample

  • can also use a biosensor
  • higher Conc higher the absorbance?
49
Q

How do we create a calibration curve ?

A
  • take a series of known concentrations of reducing sugar. Using a sample of each carry out benedicts test. Carry out a colorimeter test and Record the percentage transmission of light through each supernatant then ploy a graph to show transmission of light against the concentration of reducing sugar.
50
Q

What is the difference between a saturated and unsaturated fatty acid ?

A
  • saturated fatty acids do not have a double carbon bond whereas unsaturated fatty acids do.
51
Q

What is the structure of phospholipids?

A

1 glycerol molecule, two fatty acids with a phosphate group molecule

52
Q

properties of water

A
  • they have a high boiling point = lots of energy is needed to break the hydrogen bonds so therefore creates a stable water temperature for aquatic animals; less energy is spent on temperature control

-Ice is less dense than water= creates an insulating barrier as water doesnt freeze below allowing organisms to move under water. and can create a habitat for polar bears on top on the ice.

-acts as a solvent to allow mineral ions to be transported around animals and plants

-transport medium- allows the transport of soluble substances

  • high specific heat capacity= creates a stable temperature for enzymes to work at their optimum temperature.

-high latent heat of vaporisation so can be a cooling mechanism in mammals e.g. via sweat

  • cohesion= hydrogen bonding in water which creates a high surface tension for insects like water skaters to walk on
53
Q

what chemical elements make up lipids

A

carbon, hydrogen and oxygen

54
Q

what chemical elements make up a protein

A

-carbon, hydrogen, oxygen, nitrogen and sulfur

55
Q

what chemical elements make up a nucleic acid

A
  • carbon, hydrogen, oxygen, nitrogen and phosphate
56
Q

Function of cholesterol

A
  • 4 carbon ring structure
  • regulate fluidity
57
Q

Structure of cholesterol ( from exam question)

A
  • Peptide bonds between amino acids in polypeptide
    -every 3rd amino acid is glycine
    -cool
    -glycine allows closeness
    -hydrogen bonds between polypeptide chains
    -no hydrophilic groups on outsides
    -adjacent molecules joined by crosslinks

Biology (26 decks)

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