A 1.2 nucleic acids- IB bio HL

genetic material

a store of informatin

what happens if genetic material is copied?

it can be passed from parent to offspring

what is genetic material sometimes called because it is inherited?

hereditary information

why do all living organisms use DNA?

to store hereditary information

what is the full name for dna

deoxyribonucleic acid

where were nucleic acids first discovered?

in the cell nucleus

what is the size of nucleic acids?

very large

what are nucleic acids made up of

nucleotides

what do some viruses do?

use RNA as their genetic material

what do nucleotides consist of?

• pentose sugar

• phosphate group

• nitrogenous base

how are the base and phosphate of a nucleotide linked?

covalent bonds to the pentose sugar

how do nucleotides link together into a chain or polymer?

covalent bonds form between the phosphate of one nucleotide and another sugar of the next nucleotide

what are the bases in DNA?

adenine, thymine, cytosine, guanine

what are the bases in RNA?

adenine, uracil, cytosine, guanine

how many types of nucleotides are there in dna and why?

four types because each nucleotide contains one base

what two nucleotides can be linked to each other?

any two nucleotides because the phosphate and sugar used to make the bond are the same

how is information stored?

the sequence of bases- information is stored in a coded form

how are nucleotides linked in RNA?

condensation reaction

what are the pentose sugars in each DNA nucleotide?

deoxyribose

what does a DNA molecule consist of in terms of its structure?

two strands of nucleotides linked to each other by their bases

what are the links between the bases of nucleotides?

hydrogen bonds

how are the two strands of nucleotides in DNA organized?

• anti parallel

• one strand ends with phosphate group

• the other strand ends with deoxyribose

what are some differences between the two nucleic acids?

• double stranded v single stranded

• different nitrogenous bases (thymine v uracil)

• deoxyribose v ribose sugar

what is complementary base pairing?

in DNA, only certain bases can pair

• adenine → thymine

• cytosine → guanine

what does complementary base pairing allow?

an exact copy of a DNA molecule to be made during replication

how are new strands of nucleic acid formed?

by adding nucleotides one by one and linking them together

before being added to a strand, what must each nucleotide that is added do?

must be carrying the base that is complementary to the next base on the template strand

what is semi conservative replication?

replication changes one original DNA molecule into two identical DNA molecules each with one strand from the original and one new strand

what does genetic information consist of?

sections of DNA called genes

what does each gene consist of?

information needed for a particular purpose

what is gene expression

when information in a gene has a effect on the cell

what is the first stage of expressing a gene

transcription

what roles can rna produced by transcription have?

regulatory or structural role in the cell or in protein synthesis

what happens to synthesize a protein?

the base sequence of the RNA molecule is translated into the amino acid sequence of a protein, complementary base pairing is involved

when is genetic information decoded?

protein synthesis

what are codons?

groups of three bases that have meanings in the code

what meanisn can codons have?

• most codons specific one amino acid

• one codon signals protein synthesis starting

• three codons signal that protein synthesis should stop

what chemical groups are the nitrogenous bases in DNA?

• adenine and guanine which are purine bases with molecules that have two rings of atoms

• cytosine and thymine pyrimidine bases with molecules that only have one ring of atoms