2.3 Nucleotides + Nucleic acids

Question 1

Components of DNA nucleotide?

Answer 1

Deoxyribose (polymer of nucleotide, phosphate group, and one organic base (adenine, cytosine, guanine or thymine)

Question 2

Components of RNA nucleotide?

Answer 2

Ribose (polymer of nucleotide) , a phosphate group, and one organic base (adenine, cytosine, guanine or uracil)

Question 3

Nucleotides join together by?

Answer 3

Phosphodiester bonds
- Condensation

Question 4

DNA and RNA both…?

Answer 4

Carry information

Question 5

What does RNA do?

Answer 5

RNA transfers genetic info from DNA to ribosomes

Question 6

What does DNA do?

Answer 6

DNA holds genetic information

Question 7

Nucleotides consists of..?

Answer 7

Pentose (5 carbon sugar), organic base and phosphate group

Question 8

DNA molecules are…

Answer 8

Double helix, composed of 2 polynucleotides joined together by hydrogen bonds.

Question 9

RNA molecules are…

Answer 9

Short and single polynucleotide chains

Question 10

What is ATP?

Answer 10

Adenosine Trisphosphate = contains base adenine, sugar ribose and 3 phosphate group

Question 11

What does ATP and ADP do?

Answer 11

Store and transports energy in cells

Question 12

Adenine and Guanine bases are called?

Answer 12

Purine

Question 13

Cytosine and Thymine bases are called?

Answer 13

Pyrimidine

Question 14

What are purines?

Answer 14

Two C nitrogen rings joined together

Question 15

What are pyrimidine?

Answer 15

One C nitrogen rings
(smaller)

Question 16

What is ADP?

Answer 16

Adenosine Triphosphate = contains base adenine, sugar ribose and 2 phosphate groups

Question 17

When energy is used ADP + P turns into..

Answer 17

ATP

Question 18

When energy is released ATP turns into…

Answer 18

ADP

Question 19

Nucleotides join together to form?

Answer 19

Polynucleotides

Question 20

Two polynucleotides strands join together to form?

Answer 20

Double helix - 2 DNA strands join by H bonding between bases

Question 21

Complementary pairing?

Answer 21

A - T
G - C

Question 22

Self replication of DNA?
(SEMI CONSERVATIVE = ONE NEW STRAND, ONE ORIGINAL)

Answer 22

• Double helix unwinds, H bonds between complementary bases break using DNA helicase (enzyme), this separates two strands of DNA
• Both strands are used as templates, complementary base pairing occurs between the template + free nucleotides
• Adjacent nucleotides are joined by phosphodiester bonds (condensation) using DNA polymerase (enzyme)

Question 23

What is a gene?

Answer 23

Sequence of DNA nucleotides that codes for a protein

Question 24

Each amino acid is coded by a sequence of…

Answer 24

Three bases (triplet)

Question 25

what is a triplet code?

Answer 25

Read in groups of 3 bases

Question 26

Three bases are?

Answer 26

A codon

Question 27

What is a codon?

Answer 27

Represents one amino acid

Question 28

What is mRNA?

Answer 28

Messenger RNA (complementary to DNA) - made in nucleus - carries genetic code to cytoplasm, used to make a protein in translation

Question 29

What is tRNA?

Answer 29

Transfer RNA (found in cytoplasm carries amino acids to ribosomes) - found in cytoplasm has amino acid binding site carries amino acids to ribosomes during translation

Question 30

What is rRNA?

Answer 30

Ribosomal RNA (found in ribosomes) - forms two subunits in a ribosome moves along mRNA strand in synthesis, helps catalyse formation of peptide bonds

Question 31

Genetic code is non overlapping and this means?

Answer 31

Base triplets don’t share bases.

Question 32

Genetic code is degenerate and this means?

Answer 32

Amino acids can be coded for by more than one codon 64 combinations -> 20 amino acids

Question 33

Genetic code is universal and this means?

Answer 33

All organisms use the same base code (ATGCU)

Question 34

What is transcription?

Answer 34

First stage of protein synthesis. During this a copy of mRNA copy of a gene (section of DNA) is made in the nucleus

Question 35

Transcription steps?

Answer 35

DNA unwinds, unzips mRNA strand built free RNA nucleotides pair up (complementary) sugar phosphate backbone bonded by RNA polymerase hydrogen bonds break (mRNA + DNA) mRNA leaves nucleus

Question 36

What is translation?

Answer 36

Occurs at the ribosomes in the cytoplasm. During this, amino acids are joined together to make a polypeptide chain (protein) following the sequence of codons carried by the mRNA

Question 37

Translation steps?

Answer 37

mRNA moves to ribosomes, binds to subunit of ribosome tRNA (with complementary anticodons) binds to mRNA start codon specific amino acids attached to tRNA, start codon codes for methionine (AUG) peptide bonds formed between amino acids (condensation reactions) catalysed by peptidyl transferase stop codon - end of polypeptide chain