Biological Molocules 2

Question 1

What makes up a nucleotide?

Answer 1

5-carbon pentose sugar
Nitrogen-containing base
Phosphate group

Question 2

What is the pentose sugar in RNA?

Answer 2

Ribose

Question 3

What is the pentose sugar in DNA?

Answer 3

Deoxyribose

Question 4

What is the difference between a purine and a pyramidine?

Answer 4

A purine has two nitrogen-containing rings and pyramiding has one

Question 5

What are the most common purines?

Answer 5

Adenine

Guanine

Question 6

What are the most common pyramidines?

Answer 6

Cytocine
Thymine (DNA)
Uracil (RNA)

Question 7

Do nucleotides carry a positive or negative charge?

Answer 7

Negative

Question 8

What reaction joins the components of a nucleotide?

Answer 8

Condensation reaction

Question 9

What is ATP?

Answer 9

The universal energy supplier in cells

Question 10

How does the structure of ATP help it carry out it’s function?

Answer 10

The third phosphate bond in the molocule is broken in hydroysis catalysed by ATPase to produce ADP which makes energy

Question 11

What catalyses the hydrolysis of ATP molocules?

Answer 11

ATPase

Question 12

What is the function of nucleic acids?

Answer 12

They carry the information needed to form new cells when copied onto mRNA. It stores genetic information in chromasomes

Question 13

What are nucleic acids?

Answer 13

Chains of nucleotides linked together by condensation reactions that produce phosphodiester bonds between the sugar on one nucleotide and the phosphate group on the next.

Question 14

What bond is in the sugr-phosphate backbone?

Answer 14

Phosphodiester

Question 15

What is the difference between DNA and RNA?

Answer 15

RNA: Single stranded and can fold into complex shapes held together by hydrogen bonds
DNA: Double helix with the sugar-phosphate backbone on the outside and the bases inside held by hydrogen bonds

Question 16

What bond holds the bases of the two DNA strands together?

Answer 16

Hydrogen

Question 17

How many hydrogen bonds are there between bases C and G?

Answer 17

three

Question 18

How many hydrogen bonds are there between bases A and T?

Answer 18

two

Question 19

Why are the strands called 3 prime and 5 prime?

Answer 19

Depends on which carbon atom in the pentose sugar that the first phosphate group in the chain is attatched to

Question 20

What was the conservative model of replication?

Answer 20

The original double helix stays intact and the new helix is made up of entirely new material

Question 21

What is the semi-conservative model of replication?

Answer 21

The DNA is unzipped with new nucleotides lining up along each strand so each new helix had half of the original material and half of the new material

Question 22

How does DNA replicate?

Answer 22

Semi-conservatively
DNA helicase unzips the strands
Free nucleotides join to the exposed bases to form matching pairs
DNA polymerase links the nucleotides along the template strand
DNA ligase catalyses the formation of phosphodiester bonds

Question 23

What role does DNA helicase play in replication?

Answer 23

It unzips the two strands of DNA along the hydrogen bonds

Question 24

What role does DNA polymerase play in replication?

Answer 24

Catalyses the linking up of nucleotides along the template strand, creating new hydrogen bonds

Question 25

What is the role of DNA ligase in replication?

Answer 25

It catalyses the formation of phosphodiester bonds along the sugar-phosphate backbone

Question 26

How is DNA a triplet code?

Answer 26

A sequance of three bases code for each amino acid which are arranged together in a polypeptide chain

Question 27

What is a codon?

Answer 27

A sequance of three bases in DNA or RNA

Question 28

What does T/U bond with?

Answer 28

A

Question 29

What does C bond with?

Answer 29

G

Question 30

Why is it a good thing that DNA is non-overlapping?

Answer 30

A point mutation will only affect a single amino acid

Question 31

What are the main functions of RNA in protein synthesis?

Answer 31

To carry instructions for a polypeptide from the DNA in the nucleus to the ribosomes where proteins are made It picks up specific amino acids from the protoplasm and carries them to the surface of the ribosomes It makes up most of the ribsomes themselves

Question 32

Where is mRNA formed?

Answer 32

The nucleus

Question 33

What is the antisense strand?

Answer 33

mRNA

Question 34

What is the sense strand?

Answer 34

DNA

Question 35

How is mRNA created?

Answer 35

The DNA unravels by RNA-directed DNA polymerase and complimentry bases line up alongside the sense strand. Phosphodiester bonds are catalysed along the backbone of the mRNA by RNA polymerase

Question 36

How is the mRNA able to pass through the nuclear envelope?

Answer 36

It's small enough to pass through the pores

Question 37

What is the purpose of mRNA?

Answer 37

To carry instructions for a polypeptide from the DNA in the nucleus to the ribosomes where proteins are made

Question 38

What is the purpose of tRNA?

Answer 38

It picks up specific amino acids from the protoplasm and carries them to the surface of the ribosomes

Question 39

What is the purpose of rRNA?

Answer 39

It makes up most of the ribsomes themselves

Question 40

Where is tRNA found?

Answer 40

The cytoplasm

Question 41

What is an anticodon?

Answer 41

The sequance of three bases found on tRNA

Question 42

How is a polypeptide created?

Answer 42

The mRNA travels to the ribosome where tRNA with the complimentry anticodon binds. The amino acids on the other end of the tRNA join together as the mRNA travels through the ribosome, peptide bonds forming between them.

Question 43

Where is rRNA found?

Answer 43

It is made in the nucleus but makes up 50% of the ribosomes.

Question 44

What is a mutation?

Answer 44

A permenant change in the DNA of an organism

Question 45

How can the body deal with mutations?

Answer 45

It has specific restriction enzymes to cut out or repair broken strands of DNA

Question 46

What are point mutations?

Answer 46

Only one nucleotide is miscopied during transcription

Question 47

What are some different types of point mutations?

Answer 47

Deletion Substitution Insertation

Question 48

What is a chromasomal mutation

Answer 48

Changes of the position of genes in chromasomes

Question 49

What is a whole-chromasome mutation?

Answer 49

An entire chromasome is either lost or gained during meiosis