dc2 flashcards

Question 1

dna function

Answer 1

The function of DNA is to hold or store genetic information
DNA is the molecule that contains the instructions for the growth and developmen of all organisms

Question 2

rna

Answer 2

The function of RNA is to transfer the genetic code found in DNA out of the nucleus and carry it to the ribosomes in the cytoplasm
Ribosomes are where proteins are produced - they ‘read’ the RNA to make polypeptides (proteins) in a process known as translation

Question 3

what is a nucleotide formed from

Answer 3

A pentose sugar (a sugar with 5 carbon atoms)
A nitrogen-containing organic base
A phosphate group

Question 4

dna nucleotides

Answer 4

The components of a DNA nucleotide are:
A deoxyribose sugar with hydrogen at the 2’ position
A phosphate group
One of four nitrogenous bases - adenine (A), cytosine(C), guanine(G) or thymine(T)

Question 5

RNA nucleotides

Answer 5

A ribose sugar with a hydroxyl (OH) group at the 2’ position
A phosphate group
One of four nitrogenous bases - adenine (A), cytosine(C), guanine(G) or uracil (U)

Question 6

what makes rna more suseptible to hyrolysis

Answer 6

The presence of the 2’ hydroxyl group
This is why DNA is the storage molecule and RNA is the transport molecule with a shorter molecular lifespan

Question 7

what are purines

Answer 7

adenine and guanine
they have a double ring structure

Question 8

pyramidines

Answer 8

The bases cytosine, thymine and uracil
they have a single ring structure

Question 9

phopshodiester bonds

Answer 9

DNA and RNA are polymers (polynucleotides), meaning that they are made up of many nucleotides joined together in long chains

Separate nucleotides are joined via condensation reactions

A condensation reaction between two nucleotides forms a phosphodiester bond

Question 10

what is sugar phosphate backbone

Answer 10

The chain of alternating phosphate groups and pentose sugars produced as a result of many phosphodiester bonds

Question 11

dna polynucleotide strand

Answer 11

two polynucleotide strands
antiparallel
alternating deoxyribose sugars and phosphate groups bonded together to form the sugar-phosphate backbone.
The phosphodiester bonds link the 5-carbon of one deoxyribose sugar molecule
to the phosphate group from the same nucleotide,
3’ end and a 5’ end

Question 12

Hydrogen bonding

Answer 12

two antiparallel DNA polynucleotide strands that make up the DNA molecule are held together by hydrogen bonds between the nitrogenous bases
complementary base pairing
DNA base pairs

Question 13

strucutre of rna

Answer 13

• one polynucleotide strand
  -augc
  -pentose sugar ribose
  -shorter
  -alternating ribose sugars and phosphate groups linked together
  -sugar-phosphate bonds are covalent phopshodiester bonds

Question 14

ribsomes

Answer 14

• site of protein synthesis,They ‘read’ RNA to make polypeptides (proteins) in a process known as translation

Question 15

semi conservative replication

Answer 15

in each new DNA molecule produced, one of the polynucleotide DNA strands (half of the new DNA molecule) is from the original DNA molecule being copied
The other polynucleotide DNA strand (the other half of the new DNA molecule) has to be newly created by the cell
the new DNA molecule has conserved half of the original DNA and then used this to create a new strand