DNA

Question 1

What are Nucleic Acids and name the two different types.

Answer 1

-Nucleic Acids are organic molecules that control the synthesis of proteins and transferring of genetic info.
-Two types:
-DNA (deoxyribonucleic acid)
-RNA (ribonucleic acid)

Question 2

Where is DNA found?

Answer 2

-Mainly occurs in the nucleus in the form of chromosomal DNA

-Can also occur in the mitochondria and chloroplast and is called Extranuclear DNA

Question 3

Structure of DNA
-state whether it is single or double stranded.
-state the parts of the nucleotide.

Answer 3

-DNA is double stranded to form a double helix
-Nucleotide consists of three parts
-sugar molecule - deoxyribose
-phosphate group
-nitrogenous base

Question 4

What are the different nitrogenous bases for DNA (4 types)
How do they pair?

Answer 4

Large Molecules = purine bases:
-Adenine (A)
-Guanine (G)
Small Molecules = pyrimidine bases:
-Cytosine (C)
-Thymine (T)

They will pair as:
A - T
G - C

Question 5

Definition of Gene

Answer 5

Short segments of DNA with a specific sequence of nitrogenous bases.

Question 6

What does DNA carry?

Answer 6

DNA carries genetic code for the synthesis of proteins.

Question 7

What percentage of DNA in living cells code for proteins?

What does the remaining percentage do and what is it called?

Answer 7

~2% of DNA in living cells codes for proteins

• The other 98% is called Non Coding DNA
  (Junk DNA)

Question 8

What does Junk DNA do?

Answer 8

It is used in fingerprints

Question 9

What does mtDNA stand for and what does it code for?

Answer 9

Mitochondrial DNA - mtDNA
- circular in shape
- codes for the enzymes that control cellular respiration.

Question 10

What does RNA stand for and where is it found?

Answer 10

-RNA stands for ribonucleic acid
- it is found in the nucleus and cytoplasm and in some parts of ribosomes

Question 11

RNA structure
-State whether it is double or single strand
-State the parts of the RNA nucleotide

Answer 11

-Single strand
-Nucleotide
-Sugar molecule - ribose
-phosphate group
-Nitrogenous bases

Question 12

What are the different nitrogenous bases for RNA? (4 types)

How to they pair?

Answer 12

Large Molecules = purine bases:
-Adenine (A)
-Guanine (G)
Small Molecules = pyrimidine bases:
-Cytosine (C)
-Uracil (U)

A - T
U - A
G - C
C - G

Question 13

What are the different types of RNA

Answer 13

• Messenger RNA (mRNA)
• Transfer RNA (tRNA)
• Ribosomal RNA (rRNA)

Question 14

-What is the structure of mRNA?
-Where is it formed?
-What does it do?

Answer 14

• Single Strand with unlimited nucleotides
• Formed in the nucleoplasm using DNA as template
• Carries genetic code from DNA in the nucleus to ribosomes in the cytoplasm
  -nitrogenous bases on the mRNA - codon

Question 15

What is the structure of tRNA?
Where does it occur
What are the three exposed bases called?
What does it do?

Answer 15

-It is single stranded that folds in on itself to form loops.
-Occurs in the cytoplasm
-The three exposed bases are called anticodon
-It picks up amino acids and takes them to the ribosomes.

Question 16

What is DNA Replication necessary for?

Answer 16

It is necessary for cell division.

Question 17

DNA is duplicated to form?

Answer 17

DNA is duplicated to form 2 identical copies.

Question 18

What are the identical copies called?
What else will duplicate?

Answer 18

-The identical copies are called chromatids.
- The histones also duplicate

Question 19

When does DNA replication take place?

Answer 19

• Takes place during interphase

Question 20

What is protein synthesis?

Answer 20

-Protein synthesis is the process in which proteins are manufactured in living cells

Question 21

What controls the synthesis of proteins?
What are proteins made up of?

Answer 21

• DNA and RNA control the synthesis of proteins.
• proteins are made up of amino acids.

Question 22

In order to make a certain protein, specific types of amino acids needs to be joined in a specific sequence.
Where does this sequence come from?

Answer 22

The sequence comes from our DNA (genes)

Question 23

What provides a code for a particular amino acid?

Answer 23

-Codon
- they determine the sequence in which amino acids will link

Question 24

What are the steps in protein synthesis?

Answer 24

-Transcription of DNA
-Translation of RNA to proteins.

Question 25

What is step one in

Question 26

What does the helicase do?

Answer 26

The helicase breaks the weak hydrogen bonds and unzips the DNA strands.

Question 27

What does the DNA polymerase do?

Answer 27

This molecule replicates DNA strands to build new strands of DNA

Question 28

DNA