Brainscape's Knowledge GenomeTM

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


See full index

Biology Year 1 > Topic 1B- More Biological Molecules > Flashcards

Topic 1B- More Biological Molecules Flashcards

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

What is the function of DNA?

A

Used to store genetic information

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

What is the function of RNA?

A

To transfer genetic information from the DNA to the ribosomes

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

DNA and RNA are polymers of what type of biological molecule?

A

Nucleotides

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

What are nucleotides made up of?

A
  • a pentose sugar
  • a nitrogen-containing organic base
  • a phosphate group
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are the four bases in DNA?

A

Adenine
Thymine
Cytosine
Guanine

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

Name 4 differences between DNA and RNA

A
  • RNA contains nucleotides with a ribose sugar not deoxyribose
  • RNA is single stranded, DNA is double stranded
  • RNA has the base uracil while DNA has the base thymine
  • RNA is much shorter than DNA polynucleotides
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What type of reaction do nucleotides join via?

A

Condensation, between the phosphate group of one nucleotide and the sugar of another

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

What bond is formed between a phosphate of one nucleotide and the sugar of another?

A

Phosphodiester bond

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

What is the sugar-phosphate backbone?

A

A chain of sugars and phosphates

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

What are the base pairs in DNA?

A

AT
CG

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

What type of bond is formed between bases?

A

Hydrogen

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

DNA strands are antiparallel. What does this mean?

A

They run in opposite directions.

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

What type of replication does DNA replicate by?

A

Semi-conservative replication

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

Describe what happens in DNA replication

A
  1. Enzyme DNA helicase breaks down hydrogen bonds between bases on the two polynucleotide strands
  2. Each original single strand acts as a template for a new strand. CBP means that free floating DNA nucleotides are attracted to their complementary bases on the original template strand
  3. Condensation reactions join the nucleotides of the new strands together- catalysed by the enzyme DNA polymerase. Hydrogen bonds form between bases between new and original strands.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Why does DNA polymerase move in opposite ways along DNA strands?

A

Each end of DNA is called 3’ and 5’
The active site of DNA polymerase is only complementary to the 3’ end. So the enzyme can only add nucleotides to the new strand at the 3’ end.

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

Meelson and Stahl used to isotopes of what element to prove DNA replication was semi-conservative?

A

Nitrogen- 15N and 14N

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

Describe Meelson and Stahl’s experiment

A

1) Two samples of bacteria were grown in a nutrient broth containing light nitrogen and heavy nitrogen. As bacteria reproduced, they took up nitrogen from the broth to help make nucleotides for the new DNA.
2) A sample of DNA was taken from each batch of bacteria, and spun in a centrifuge. The DNA from the heavy nitrogen bacteria settled lower down the centrifuge tube because its heavier.
3) Then the bacteria grown in the heavy nitrogen broth were taken out and put in the broth containing only light nitrogen. They were left for one round of replication, and then taken out and spun in the centrifuge.
4) DNA settled out in the middle, showing it contained a mixture of light and heavy nitrogen.

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

What is ATP?

A

The immediate source of energy in a cell

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

Can a cell get its energy directly from glucose?

A

No

20
Q

What is ATP made from?

A
  • nucleotide base adenine
  • ribose sugar
  • three phosphate groups
21
Q

Why is ATP known as a nucleotide derivative?

A

Because its a modified form of a nucleotide.

22
Q

How does ATP get into the cell that needs energy?

A

It can diffuse into it

23
Q

How is the energy in ATP stored?

A

It is stored in high energy bonds between the phosphate groups

24
Q

What type of reaction is the breakdown of ATP?

A

Hydrolysis

25
Q

What happens in the breakdown of ATP?

A

ATP → ADP (adenosine diphosphate) + Pi
Phosphate bond broken and energy is released
Reaction catalysed by the enzyme ATP hydrolase

26
Q

What type of reaction is the re-synthesis of ATP?

A

Condensation

27
Q

When can the re-synthesis of ATP happen?

A

during respiration and photosynthesis

28
Q

What happens in the re-synthesis of ATP?

A

ADP + Pi → ATP
Catalysed by the enzyme ATP synthase

29
Q

What can happen to the otherwise ‘wasted’ products of ATP hydrolysis?

A

The energy released can be used in other energy- requiring reactions in the cell- this means the energy isn’t lost as heat
The released phosphate can also be put to use- it can be added to another compound (phosphorylation), which often makes the compound more reactive.

30
Q

What is a metabolite?

A

A substance involved in a metabolic reaction. Water is an example of this.

31
Q

What are some examples of reactions water is involved in?

A

Condensation
Hydrolysis

32
Q

Why is water considered a polar molecule?

A

because the shared negative hydrogen electrons are pulled towards the oxygen atom, the other side of each hydrogen atom is left with a slight positive charge.

33
Q

How does hydrogen bonding occur in water?

A

The slightly negatively-charged oxygen atoms attract the slightly positive hydrogen atoms of other water molecules.

34
Q

What are the five useful properties of water?

A
  1. Important metabolite
  2. High latent heat of vaporisation
  3. Can buffer (resist) changes in temperature
  4. Good solvent
  5. Strong cohesion between molecules
35
Q

Describe why water is an important metabolite

A

Many metabolic reactions involve a condensation or hydrolysis reaction.

36
Q

Why is it important for living organisms for water to have a high latent heat of vaporisation?

A

They can use water loss through evaporation to cool down as it takes a lot of energy (heat) to break the bonds.

37
Q

Why is important that water can buffer changes in temperature?

A

It means that water doesn’t experience rapid temperature changes. This makes it a good habitat because the temperature under water is likely to be more stable than on land. The water inside organisms also remains at a fairly stable temperature- helping them to maintain a constant internal body temperature.

38
Q

What makes water a good solvent?

A

Water’s polarity makes it a good solvent, because water is polar, the positive end of the water molecule will be attracted to the negative ion (that is dissolved in water) and the negative end vice versa. This means the ions will get totally surrounded by water molecules- they’ll dissolve.

39
Q

What is the definition of cohesion?

A

The attraction between molecules of the same type.

40
Q

Why is it important that water has a strong cohesion between its molecules?

A

Water molecules are very cohesive because they are polar.
Strong cohesion helps water to flow, so it is good for transporting substances. e.g. xylem
It also means that water has a high surface tension when it comes into contact with air, e.g. sweat droplets, pond skaters walking on water

41
Q

What is an inorganic ion?

A

An ion that does not contain carbon

42
Q

Where can you find inorganic ions?

A
  • cytoplasm’s of cells
  • in solution
  • in the body fluids of organisms
43
Q

What ions are a part of haemoglobin?

A

Iron ions

44
Q

What does the Fe2+ ion do in haemoglobin?

A

It binds to the oxygen

45
Q

What does the concentration of hydrogen ions effect?

A

pH

46
Q

What do sodium ions help to do?

A

They help to transport glucose and amino acids across membranes. (co-transport)

47
Q

Name 3 molecules that contain phosphate ions

A

ATP
DNA
RNA

Biology Year 1 (9 decks)

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