Session 2-Introduction To DNA Flashcards Preview

Semester 1-MCBG > Session 2-Introduction To DNA > Flashcards

Flashcards in Session 2-Introduction To DNA Deck (12):
1

Which groove is used for DNA protein binding and why?

Major groove because it has the most space for protein to bind to

2

How is 2m of DNA packaged in a cell?

DNA wraps around special proteins called HISTONES which form loops of DNA called NUCLEOSOMES. These nucleosomes coil and stack together to form fibres called CHROMATIN. This in turn forms larger loops and coils to form CHROMOSOMES.

3

What is a gene?

Basic unit of genetic information, carried on a specific locus on a chromosome

4

What are nucleic acids?

Polynucleotides (linear polymers of nucleotides)

5

What are the two types of pentose sugars?

Ribose (in RNA)-OH on 2C
2-deoxyribose (in DNA)-H on 2C

6

Which bases are purines? (Remember: angels are pure)

Adenine and Guanine

7

Which bases are pyrimidines?

Cytosine
Thymine
Uracil (RNA)

8

How are nucleotides joined?

Phosphodiester bonds

9

Describe the polarity in a DNA molecule

The chain has a 5'P (phosphate end of the chain) and a 3'OH (OH on 3C in deoxyribose)

10

How many hydrogen bonds are between G and C?

3

11

How many hydrogen bonds are between A and T or A and U?

2

12

What is the conventional way of depicting a DNA sequence?

5' to 3' from left to right and the top strand is always 5' to 3'

NOTE: always write complementary strand from 5', regardless of 3' start