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Flashcards in Structure Of RNA and DNA Deck (17)
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1

What is a nucleotide made up of?

A pentose sugar

A phosphate group

Organic base-Adenine, Thymine, Cytosine, Guanine

2

How are the pentose sugar, phosphate group and organic base joined together?

Condensation reactions

3

How can 2 nucleotides be joined together? What bond is formed between them?

A result of a condensation reaction between the deoxyribose sugar of one of the nucleotides and a phosphate group of another

Phosphodiester bond

4

What is a polynucleotide?

The continued linking of nucleotides forms a long chain called a polynucleotide

5

What is the pentose sugar always in rna

Ribose

6

What are the organic bases in RNA?

Adenine, Uracil, Guanine, Cytosine

7

In DNA what is the pentose sugar?

Deoxyribose

8

What are the organic bases in DNA

Adenine, thymine, guanine, cytosine

9

DNA is made up of 2 strands of nucleotides. What are they joined together by?

Hydrogen bonds

10

Which bases are complimentary to each other?

Adenine and Thymine
Guanine and Cytosine

11

How many hydrogen bonds are there between adenine and Thymine and Cytosine and guanine?

2 between T and A
3 between C and G

12

What makes DNA a stable molecule?

The phosphodiester backbone protects the more chemically reactive bases inside the double helix

Hydrogen bonds link the organic base pairs forming bridges between the phosphodiester uprights, as there are 3 bonds between C and G, the higher the proportion of C-G pairings, the more stable the DNA molecule

13

How is the DNA molecule adapted to carry out its functions?

Very stable structure, which normally passes from generation to generation without change. Only rarely does it mutate.

Two separate strands are joined only with hydrogen bonds, which allow them to separate during DNA replication and protein synthesis

It's an extremely large molecule and therefore carries an immense amount of genetic information

By having the base pairings within the helical cylinder of the deoxyribose phosphate backbone, the genetic info is to some extent protected from being corrupted by outside chemical and physical forces

Base pairings lead to DNA being able to replicate and to transfer information as mRNA

14

List 3 basic components of a nucleotide

pentose sugar, phosphate group, organic base

15

suggest why the base pairings of adenine and cytosine and guanine and thymine do not occur

the bases are linked by H bonds. the molecular structures could be such that H bonds do not form between adenine and cytosine and between guanine and thymine

16

if the bases on one strand of the dna are TGGAGACT, determine the base sequence of the other strand

ACCTCTGA

17

if 19.9% of the base pairings in human dna are guanine, calculate what percentage of human dna is thymine. show your reasoning

30.1%

G+C=19.9+19.9=39.8

100-39.8=60.2%
A+T=60.2%
T=30.1%