More biological molecules Flashcards
1
Q
What are the monomers of DNA + RNA?
A
Nucleotides
2
Q
What are nucleotides made from?
A
- Nitrogen containing organic base
- Pentose sugar
- Phopshate group
3
Q
Outline the structure of DNA nucleotide
A
- Pentose sugar: deoxyribose
- Has phosphate group
- Bases: adenine, cytosine, thymine + guanine
4
Q
Outline the structure of RNA nucleotide
A
- Pentose sugar: ribose sugar
- Phosphate group
- Base: uracil
5
Q
What bond forms between a phosphate group + sugars?
A
Phosphodiester bond
6
Q
What is the chain of sugars + phosphates known as?
A
Sugar-phosphate backbone
7
Q
Outline the structure of DNA
A
- 2 DNA polynucleotide strands joined together by H bonds btw bases
- W/ complimentary base pairing
- Joined during condensation reaction
- 2 H bonds btw A + T
- 3 H bonds btw C + G
- Double helix
- Strands are antiparallel
8
Q
Outline the structure of RNA
A
- Single polynucleotide chain
- Shorter than DNA polynucleotides
9
Q
Outline DNA replication by semi-conservative replication
A
- DNA helicase breaks H bonds btw bases, helix unwind
- OG strand acts as template
- Free floating DNA nucleotides attracted to complimentary base pair on template strand using complimentary base pairing
- Condensation reaction joins nucleotides catalysed by DNA polymerase, H bonds form
- Each DNA strand contains 1 OG strand + new strand
10
Q
Outline the study for the evidence for semi-conservative replication
A
- 2 samples of bacteria grown, 1 nutrient containing light N + 1 in heavy, as bacteria reproduced they took up N to help make nucleotides
- Sample of DNA taken from bacteria + spun in centrifuge, DNA from heavy settled lower down centrifuge tube
- Bacteria grown in heavy put into broth containing light N, left for 1 round of DNA replication, sampled + centrifuged
- If SC, bacteria would contain 1 old heavy + new light so DNA will settle in middle
11
Q
What are the properties of water?
A
- Metabolite - condensation + hydrolysis
- High latent heat of vaporisation - lots of energy to break H bonds, useful bc living organisms can use water loss through evapouration to cool down w/o losing too much
- High specific heat capacity - H bonds absorb alot of energy, useful bc living organisms don’t experience rapid temp changes, help maintain constant body temp
- Good solvent - bc water is polar, +ve end attracted to -ve ion, totally surrounded by water so dissolves
- Cohesive due to polarity - helps water flow so good as transporting substances, also high surface tension w/ air
12
Q
Outline the structure of ATP
A
- Adenine base
- Ribose sugar
- 3 phosphate groups
13
Q
When energy is needed by a cell, what happens to ATP?
A
- Broken down into ADP + Pi
- Hydrolysis reaction
- Phosphate bond broken + energy released
- Catalysed by ATP hydrolase
14
Q
How is ATP re-synthesised?
A
- Condensation reaction
- Btw ADP + Pi
- During respiration + photosynthesis
- Catalysed by ATP synthase
15
Q
What are the products from the hydrolysis of ATP used for?
A
- ATP hydrolysis coupled to other energy requiring reactions rather than lost as heat
- Pi added to another compound making it more reactive
