Brainscape's Knowledge GenomeTM

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


See full index

A LEVEL BIOLOGY > Topic 1 chap 1.3 Biological Molecules 2 > Flashcards

Topic 1 chap 1.3 Biological Molecules 2 Flashcards

1
Q

what are the 3 parts of nucleotides

A

5 carbon pentose sugar, nitrogen containing base and a phosphate group(PO4 3-)

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

What is the pentose sugar in RNA

A

ribose

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

what is the pentose sugar in DNA

A

deoxyribose- fewer oxygen atoms than ribose

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

difference between a purine and a pyrimidine base

A

purine-2 nitrogen containing rings
pyrimidine- only one nitrogen containing ring

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

name the common purines

A

adenine and guanine

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

name the common pyrimidines

A

thymine cytosine and uracil

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

what properties do nucleotides due to the presence of a phosphate group

A

acidic
negative charge

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

what does ATP stands for

A

adenosine triphosphate

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

what enzyme catalyses the hydrolysis reaction in which ATP is broken down into a ADP

A

ATPase

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

what are the products of the hydrolysis of ATP

A

(ADP) adenosine diphosphate , another nucleotide, a free inorganic phosphate group

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

define what is meant by the term nucleic acid

A

polymers made up of many nucleotides monomer units that carry all the information needed to form new cells

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

What is a phosphodiester bond

A

the bond formed between the phosphate group of one nucleotide and the hydroxyl group of the sugar of the next nucleotide in a condensation reaction

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

define the term genome

A

the entire genetic makeup of an organism

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

how many strands does DNA consist of

A

2 polynucleotide strands

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

what type of bonds is the DNA double helix held by

A

hydrogen bonds between complimentary bases

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

what is meant by saying that 2 polynucleotide strands in DNA are antiparallel

A

Means that they run in opposite directions

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

How many hydrogen bonds formed between guanine and cytosine

A

3 hydrogen bonds

18
Q

How many hydrogen bonds do adenine and thymine form

A

2 hydrogen bonds

19
Q

where is energy stored in an ATP molecule

A

in the bonds between phosphate groups

20
Q

what type of molecule is DNA

A

polymer

21
Q

how many base pairs for each complete twist of a helix

A

10 base pairs

22
Q

Outline the process of DNA replication

A

DNA HELICASE enzyme unwinds and unzips DNA breaking the hydrogen bonds that join base pairs and forming 2 separate strands

DNA polymerase lines up nucleotides along the template strand. Activated (3 PO4 -3 groups instead of 1) free nucleotides line up, only H bonds between complimentary bases at this point
2 extra PO4 -3 lost provides energy for reaction

DNA ligase joins new nucleotides to each other by strong phosphodiester bonds, forming the phosphodiester sugar backbone.

A winding enzyme winds the new strands up to form double helices

The 2 new DNA molecules are identical to the original DNA molecules

23
Q

what do we mean by saying DNA is non overlapping

A

each base is only part of one triplet/codon, each triplet/codon codes for just one amino acid

24
Q

describe the method of extracting DNA from fruit

A

+salt to separate cells and begin breaking cell wall
sieve
+detergent breaks cell membrane
+protease uncoils the DNA
to see DNA we must make it soluble so +ice cold ethanol which slows down the action of enzymes.
since ethanol is less dense it forms a layer on the top as DNA precipitates

25
Q

what is a gene

A

a section of DNA that codes for a sequence of amino acids in a polypeptide chain

26
Q

3 types of RNA

A

tRNA-transport RNA
mRNA-message RNA
rRNA- ribosomal RNA

27
Q

where does transcription take place
where does translation take place

A

transcription-nucleus
translation-cytoplasm

28
Q

Outline protein synthesis stage 1

A

Transcription-takes place in the nucleus
1. DNA double helix is separated,
2. mRNA is made using the antisense DNA strand as a template
mRNA leaves nucleus and enters cytoplasm

29
Q

outline protein synthesis stage 2

A

Translation-takes place in the cytoplasm
1.mRNA joins onto a ribosome
2.mRNA acts as a code for tRNA
3. Amino acids on neighbouring tRNA join together
4. a chain of amino acids is formed, we call this a poly-peptide.
5. the polypeptide chain folds to form a protein which is used in the cell or exported to the body.

takes place on structures called ribosomes
tRNA molecules enable amino acids attached to them to line up in the correct order.
the amino acids are joined together by the formation of peptide bonds.

30
Q

what is a polysome

A

groups of ribosomes joined by a thread of mRNA that can produce large quantities of a particular protein

31
Q

define mutation

A

a permanent change in the DNA of an organism

32
Q

what are gametes

A

haploid sex cells produced by meiosis that fuse to form a new diploid cell (zygote) in sexual reproduction

33
Q

what is a point mutation

A

It is a gene mutation , is a change in one or a small number of nucleotides affecting a single gene.

34
Q

identify and define 3 types of point/gene mutations

A

deletion -the base is completely lost

insertion -an extra base is added into a gene, which may be a repeat or a different base

substitution- one base in a gene is substituted for another

35
Q

what are chromosomal mutations

A

changes in the positions of entire genes within a chromosome

36
Q

what is a whole chromosome mutation

A

the loss or duplication of a whole chromosome

37
Q

what is sickle cell disease

A

sickle cell anaemia- human genetic disease affecting the protein chains making up the haemoglobin in red blood cells.

38
Q

what is a mutagen

A

anything that increases the rate of mutation

39
Q

identify some types of chromosomal mutations

A

inversions
gene deletion
gene duplication

40
Q

describe structure of collagen

A

fibrous proteins with little tertiary structure.
triple helix held together by hydrogen bonds, fibrils join together to form collagen fibres
long parallel polypeptide chains joined by cross links to form fibres.

41
Q

describe the structure of Haemoglobin

A

Globular protein
4 polypeptide chains joined by disulphide bonds in a quaternary structure

42
Q

difference between antisense and anticodon

A

antisense is the strand that codes for proteins while the anticodon is the name given to the sequence of 3 bases on tRNA that correspond to the bases in the mRNA codon.

A LEVEL BIOLOGY (13 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions