Structure of DNA and RNA

Where is heritable information carried?

In discrete units called genes

What are genes a part of?

Structures called chromosomes

What are chromosomes made of?

DNA and proteins

What are the two types of nucleic acids found in cells?

DNA and RNA

What is the long name for DNA?

Deoxyribonucleic acid

What is the long name for RNA?

Ribonucleic acid

Where is DNA found?

In the nucleus

Where is RNA found?

In the nucleus and cytoplasm

What are the subunits of DNA and RNA?

Nucleotides

What are the three components of a nucleotide?

5 carbon sugar, phosphate group, nitrogenous base

What is the sugar in DNA?

Deoxyribose

What is the sugar in RNA?

Ribose

What does nitrogenous mean?

Nitrogen-containing

What are the five nitrogenous bases?

Adenine, thymine, cytosine, guanine, uracil

How many rings do purines have?

2 rings

How many rings do pyrimidines have:?

1 ring

What are the purine nitrogenous bases?

Adenine and guanine

What are the pyrimidine nitrogenous bases?

Thymine, cytosine, and uracil

How are the three units of a nucleotide (sugar, phosphate, nitrogenous base) linked together?

Through two dehydration reactions

How are adjacent nucleotides linked to one another?

Further dehydration synthesis reactions

What is the Watson Crick model of DNA?

The generally recognized model of DNA, a double helix

When was the Watson Crick model of DNA created?

1953

Is DNA double stranded or single stranded?

Double stranded

What is the shape of DNA similar to?

A ladder that has been twisted into a spiral

What is the shape of DNA called?

A double helix

What are the sides of the DNA ladder made of?

Sugar and phosphate

What is the sugar phosphate backbone?

The sides of the DNA ladder made of sugar and phosphate forming the backbone of DNA

What are the rungs of the ladder made of?

Paired nitrogenous bases

How do the paired nitrogenous bases fit together?

Like puzzle pieces, complimentary base pairing

What is Chargaff’s rule?

The bases in a DNA molecule always join in a specific way

In DNA, which bases pair with which bases?

A with T, G with C

Do purines join with purines and pyrimidines join with pyrimidines, or do pyrimidines join with purines?

Purines always connect with pyrimidines

How many pairs of nucleotides form one complete turn of the helix?

10

How many turns of the helix are there in one strand of DNA?

Many thousand

How are the two strands in DNA held together?

With hydrogen bonds between the paired bases

How many hydrogen bonds are there between A and T?

2

How many hydrogen bonds are there between C and G?

3

Where is hereditary information held?

In the sequence of bases in DNA

What is a gene?

A sequence of about 1000 base pairs along a DNA molecule

How many genes are in one DNA molecule?

Many (more than 1000)

What makes up a single chromosome?

A DNA molecule linked with proteins

Is RNA single or double stranded?

Single

How and when is RNA formed?

By complimentary base pairing with one DNA strand during the process of transcription

What are the complimentary base pairs in RNA?

A with U, G with C

What are the three types of RNA?

mRNA, tRNA, and rRNA

What does mRNA stand for?

Messenger RNA

What does tRNA stand for?

Transfer RNA

What does rRNA stand for?

Ribosomal RNA