Nucleid acid structure and Organization

Question 1

Three main terms in central dogma

Answer 1

Replication: taking DNA and making more DNA
Transcription: taking DNA and making RNA
Translation: taking RNA and making proteins

Question 2

Cell Cycle G0

Answer 2

G0: resting, non dividing cells (neurons, skeletal muscle, liver, cardiac myocytes). Cells in G0-phase undergo transcription and translation but NOT replication.

Question 3

Cell Cycle G1

Answer 3

G1: cells that will grow (nucleated red cells, epithelial cells of skin, GI tracts)

Question 4

Cell Cycle S, what occurs in S-phase?

Answer 4

This where Replication takes place, only!
Recall: Replication means DNA-synthesis. At beginning of S-phase, there are 46 chrom–> at end 92!

Question 4

Where does in cell cycle does transcription take place?

Answer 4

G1, S, G2 (all together Interphase)

Question 5

Cell cycle : big picture?

Answer 5

No gene expression in M phase

Question 6

For cells in G1 phase, which signal sends them to S phase?

Answer 6

Signal to tyrosine kinase receptors (e.g from growth hormones). In cancer, something is wring with the signalling and cells to into S-phase (when they should NOT go in absence of hormones).

Question 7

Which bases you find in DNA & RNA?

Answer 7

2 subclasses :
Purines (Adenine, Guanine) &
Pyrimidines (Cytosine, Uracil, Thymine)

Question 8

How to differ purine and pyrimidines?

Answer 8

Purines have two rings. Adenine has `amino-group’ at 12 o’clock position.

Question 9

How to differ pyrimidines?

Answer 9

Question 10

Which bases are found in DNA/RNA?

Answer 10

Question 11

What is a nucleoside?

Answer 11

Base + Sugar (ribose or deoxyribose)

Question 12

What is a nucleotide?

Answer 12

Base + Sugar + Phosphate
so, AMP, ATP, ADP are nucleotides

Question 13

Differences in DNA/RNA

Answer 13

Look at the pyrimidines (single ring), is any methyl group present? if yes, then it contains thymine and it is DNA.
Look at C-2, if hydroxyl group it’s RNA.

Question 14

What is DNA/RNA made up of?

Answer 14

Nucleotides monophosphate joined together. The bond between nucelotides: Phosphodiesterase
The DNA stands are antiparallel and is held by hydrogen bonds.

Question 15

What a portion of chromosome look like?

Answer 15

Question 15

What does DNA packaging look like?

Answer 15

Portions of chromosomes are euchromatin (light-staining parts of nucleus) and others are heterochromatin (dark-staining)

Question 16

DNA packaging : big picture

Answer 16