3.1-Biological molecules Flashcards Preview

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Flashcards in 3.1-Biological molecules Deck (66)
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1
Q

Definition of monomer

A

Small units from which larger molecules are made

2
Q

Definition of polymer

A

Lots of monomers joined together

3
Q

3 Examples of monomer

A

Monosaccharides
Amino acids
Nucleotides

4
Q

What is condensation

A

Joining 2 molecules releases water

5
Q

What is hydrolysis

A

Breaking 2 molecules apart by adding water

6
Q

4 examples of monosaccharides

A

Alpha glucose
Beta glucose
Galactose
Fructose

7
Q

Difference between beta glucose and alpha glucose

A

Alpha
Hydrogen above
Beta
Hydrogen below

8
Q

Name 3 Disaccharides

A

Lactose
Maltose
Sucrose

9
Q

What makes

Lactose
Maltose
Sucrose

A

Lactose= glucose+galactose

Maltose= alpha glucose x2

Sucrose = glucose + fructose

10
Q

What is the bond made between saccharides

A

Glycosidic bond

11
Q

Name 3 polysaccharides

A

Starch
Glycogen
Cellulose

12
Q

Starch

Monomer?
Structure?
Relate to function?

A

Alpha glucose

Highly branched/ helix

Storage of glucose in plants
Compact takes up less storage
Insoluble- doesn’t affect water potential

13
Q

Glycogen

Monomer
Structure
Relates to function

A

Alpha glucose

Highly branched

Storage of glucose in body
Compact takes up less space
Insoluble

14
Q

Cellulose

Monomer
Structure
Relates to function

A

Beta glucose

Straight, unbranched chains

Provides rigidity to plant cells
Strength because of hydrogen bonds holding the fibrils together

15
Q

Biochemical test

Reducing sugar

A

Add Benedict reagent

Positive test if turns Orange / brown

16
Q

Biochemical test

Test for non-reducing sugars

A

Add HCl - hydrolysis it

Add sodium hydrogencarbonate- to neutralise

Add Benedict reagent

Positive if turns orange / brown

17
Q

Biochemical test

Test for starch

A

Add iodine

Make blue-black

18
Q

What is in a phospholipid?

A

x2 fatty acids

x1 glycerol

x1 phosphate group

19
Q

What is in a triglyceride ?

A

x3 fatty acids

x1 glyceride

20
Q

Polar or non-polar

Phospholipid?
Triglyceride?

A

Polar

Non-polar

21
Q

Roles of lipids

A
  • source of energy
  • waterproofing
  • insulation
  • protection
22
Q

Phospholipid structure properties

What they can form

A

Hydrophilic head-to water

Hydrophobic tail- away water

Form phospholipid bilayer
For cell recognition

23
Q

Triglyceride properties

A
  • high ratio of H-C so a lot of energy
  • insoluble doesn’t affect water potential
  • high ratio of H-O when oxidised makes water
24
Q

Biochemical test

Test for lipids

A

Emulsion test

Add ethanol
Add water
Cloudy-white colour = positive result

25
Q

What does saturated mean ?

A

No double bonds

26
Q

What does unsaturated mean ?

A

Double bonds present

27
Q

Structure of a amino acid

A
H       H      OH 
     \       |      / 
       N- C - C 
      /      |      \\ 
   H       R       O
28
Q

Which part of the structure is the amino group?

A
H 
   \ 
     N 
    /
H
29
Q

Which part of the group is carboxyl group ?

A
OH 
        /
     C 
        \\
          O
30
Q

What is the polymer of a protein called

A

Polypeptide

31
Q

What is the bond between amino acids

A

Peptide bond

32
Q

Explain primary structure

A

Polypeptide chains

If one amino acid changes so will the whole function

33
Q

Explain secondary structure

A

Hydrogen bonds are formed
= 3D shape
E.g. A alpha helix or beta pleated sheet

34
Q

Explain tertiary structure

A
Interaction of E groups 
=more hydrogen bonds 
=disulphide bridges 
= covalent bonds 
=ionic bonds 

Becomes more twisted

35
Q

Explain Quartenary structure

A

Add prosthetic groups

More chains

36
Q

Explain globular proteins

A

Common
Soluble
Spherical
Carry out metabolic function

E.g. Antibodies and enzymes

37
Q

Explain fibrous proteins

A
Long chains 
Run parallel 
Joined by cross bridges 
In soluble 
Linked with hydrogen bonds and disulphide bridges 

E.g. Collagen , keratin

38
Q

Biochemical test

Protein

A

Add biuret reagent

Changed to purple/ lilac colour

39
Q

What type of protein and level of structure are enzymes?

A

Globular protein

Tertiary structure

40
Q

Explain lock and key model

A

Active site complimentary to substrate

Bind together makes an enzyme- substrate complex

41
Q

What does the lock and key model not explain

A

The flexible structure of enzymes

How activation energy is lowered

42
Q

Explain the induced fit model

A

Active site and substrate are not fully complimentary

Bind together to make enzyme substrate complex

Active site changes shape slightly which puts strain on substrate

Lowers the activation energy

43
Q

What is the effect of pH on enzymes

A

Enzymes have an optimum pH

Changes in pH distorts enzyme

44
Q

What is the effect of substrate concentration on enzymes

A

As concentration increases there are more successful collisions eventually becomes a plateau because enzymes are a limiting factor

45
Q

What is a competitive inhibitor

A

Have molecular structure similar to substrate therefore can occupy the active site

46
Q

Explain non-competitive inhibitors

A

Attach themselves to anything but active site.

This denatures the enzyme by changing its shape and this means can longer be used

47
Q

What is a nucleotide

A

A monomer of DNA

48
Q

Structure of deoxyribose

A

Phosphate groups
\
Pentose sugar -nitrogenous baseball

49
Q

Structure of DNA

A
Double helix 
Antiparallel 
Form phosphodiester bonds 
Hydrogen bonds between bases 
Complimentary pairs
50
Q

What are the complimentary base pairs

A

Adenine and thymine

Cytosine and guanine

51
Q

How many hydrogen bonds between

Adenine and thymine
Cytosine and guanine

A

2 hydrogen bonds

3 hydrogen bonds

52
Q

What type of molecule is water

A

Dipolar

53
Q

What are 4 properties of water

A

High specific heat capacity

Latent heat of vaporisation

Cohesion and surface tension

Important to organisms

54
Q

Explain the high specific heat capacity of water

A

Had a high specific heat capacity

Stops sudden changes in environment which is good for aquatic environment.

55
Q

Explain latent heat of vaporisation for water

A

When water evaporates it takes energy with it providing a cooling effect

So there will be little loss of water and can still stay cool

56
Q

Explain cohesion and surface tension in water

A

Allows thin columns of water to be pulled up towards leaves through xylem vessel

57
Q

Explain waters importance to organisms

A

Used in metabolism
- hydrolysis and condensation reactions
As a solvent
- dissolve a lot of substances

58
Q

4 requirements for semi- conservative replication

A
  • Free DNA
  • Strands of DNA acts as templates
  • Need DNA polymerase
  • Need chemical energy
59
Q

Explain what happens in DNA replication

A

1) DNA helicase breaks hydrogen bonds so two strands separate
2) now there are 2 strands
3) polynucleotide acts as template to free nucleotide which bind to specific base pairs
4) nucleotides joined together by condensation reaction by enzyme DNA polymerase
5) two new DNA molecules

60
Q

What is the evidence that supports semi-conservative replication

A

Centrifuge shows a band of DNA

1st generation - both n-14 and n-15
2d generation - some n14 +n15 and some only N14

61
Q

Structure of ATP

A

🔴-🔴-🔴
\
Pentose sugar -◾️

62
Q

Show the hydrolysis and condensation of ATP

A

ATP+H2O=ADP+Pi+E

Adenine triphosphate + water = adenine diphosphate+inorganic phosphate + energy

63
Q

What enzyme is used in the ATP reaction hydrolysis

A

ATP hydrolase

64
Q

What happens when ATP is hydrolysed

A

Provides an immediate release of energy

The energy can’t be stored

65
Q

What happens in ATP reaction condensation

A

ATP synthase

66
Q

5 roles of ATP

A
  • Metabolic processes to build up molecules
  • movement energy for muscle contractions
  • active transport energy to change shape of proteins
  • secretion needed to form lysosomes
  • activation of molecules lowers activation energy