Nucleic Acids

how many base pairs per full turn of helix how long

10 base pairs 3.4 nm

Double helix

2 strands of polynucleotides coiled into a helix

how wide is double helix

2.0 nm

How much energy is released overall from one molecule?

30.6 kJ mol^-1

What is the name of the reaction that joins nucleotides

A condensation reaction

How do nucleotides link together?

A condensation reaction. The phosphate group at 5' of one nucleotide bonds covalently with the hydroxyl group at 3' of the adjacent nucleotide. This releases a water molecule and forms the sugar-phosphate backbone.

Phosphodiester bond

A covalent bond formed between the phosphate group (at 5') of one nucleotide and the hydroxyl group (at 3') of another.

Nucleic acid

A large polymer formed from nucleotides, containing the elements carbon, hydrogen, oxygen, phosphorus and nitrogen

Polymer

A long-chain molecule composed of bonded multiple monomers in a repeating pattern

Nucleotide

A monomer used to form nucleic acids, made up of a pentose monosaccharide, a phosphate group and a nitrogenous base

Polynucleotide

A polymer made up of nucleotides linked by condensation reactions

Why does this reaction release energy? in terms of bonding

A small amount of energy is needed to break relatively weak bond holding the last phosphate group in ATP A large amount of energy is released when the liberated phosphate undergoes other reactions involving bond formation

What is the reaction that shows how energy is released from ATP to provide energy for cellular activities

ATP + H2O --> ADP + Pi + energy

Which bases are purine?

Adenine and guanine

Complementary base pairing rules

Adenine and thymine Cytosine and guanine

Define Monomer

An individual molecule that makes up a polymer

Similarities between DNA and RNA

Both contain a phosphate group Adenine, cytosine and guanine bases present, phosphodiester bonds, pentose sugar, sugar-phosphate backbone

Add protease enzyme

Breaks down proteins associated with the DNA in the nuclei

what is the significance of the sequence of bases in a strand for its function?

Carries genetic information of an organism in the form of a code order of bases codes for the order of amino acids needed to make different proteins

What is the role of cellular respiration in this process?

Cellular respiration creates ATP

Similarities between ATP DNA and RNA nucleotides

Contain at least 1 phosphate group Contain a pentose sugar Contain a base

Similarities between ATP DNA and RNA

Contain at least one phosphate group Contain a pentose sugar Contain a base

What are the two main types of nucleic acid?

DNA RNA

What evidence did they find?

DNA crystals were symmetrical- strands must run antiparallel Picture of DNA B- x shaped, bases are stacked (3.4nm apart), 10 layers in every twist of helix, diameter=2nm Genes in pairs 2 phosphate-sugar backbones - on outside to attract water Placement of hydrogen (new) meant C goes with G and T goes with A so strands join in parallel

what is the result>

DNA will be seen as white strands forming between layer of sample and layer of alcohol can be picked up by spooling onto glass rod

What does the base pairing allow?

Dna to be copied and transcribed necessary for molecule of hereditary

How is energy needed/released in bonding?

Energy is needed to break bonds and released when bonds are formed

Isolation and purification of DNA by precipitation

Grind Mix with detergent Add salt Add protease enzyme Add alcohol (ethanol)

What is the reaction that breaks phosphodiester bonds?

Hydrolysis

why are the reactions of hydrolysis and energy-requiring reactions said to be 'coupled'?

Hydrolysis does not happen in isolation, only in association with energy-requiring reactions

Differences between ATP DNA and RNA nucleotides

In ATP the base is always adenine, in DNA and RNA it can be 5 bases In ATP there are 3 phosphate groups, in DNA and RNA there is only one

What is Pi?

Inorganic phosphate

WHat is the significance of double stranded, complementary base paired nature of DNA for its function?

It allows DNA to be copied and transcribed this is required for gene transcription in hereditary

Why do cells not store large amounts of ATP?

It is unstable

Components of ATP

Nitrogenous base---- adenine ALWAYS Pentose sugar---- ribose 3 phosphate groups

Strand

One chain of nucleotides Each has a phosphate group (5') and a hydroxyl group (3') at each end

What are the 3 components of a nucleotide?

Pentose monosaccharide Phosphate group (acidic and negatively charged) Nitrogenous base (containing one or two carbon rings and nitrogen)

example of transport

Pumping molecules or ions across cell membranes by active transport

2 types of nitrogenous bases

Pyrimidines Purines

Define complementary base pairing (DNA)

Specific hydrogen bonding between nucleic acid bases. Adenine binds to thymine or uracil or cytosine binds to guanine

Differences between DNA and RNA

Sugar in RNA is ribose whereas it is deoxyribose in DNA Thymine base in DNA is replaced with uracil in RNA, DNA forms double helix

Antiparallel

THe 2 parallel strands in DNA are arranged so they run in opposite directions

Sugar-phosphate backbone

The structure of many nucleotides joined together by phosphodiester bonds, with a base attached to each sugar, forming a strong chain.

Which bases are pyrimidine?

Thymine and Cytosine and Uracil

What are the 5 possible bases in nucleic acids?

Thymine, Adenine, Cytosine, Guanine and Uracil

Structure of ADP

Two phosphate groups Ribose sugar Adenine base

WHo discovered the structure of DNA

Watson and Crick

Where is the energy released in the interconversion of ATP and ADP?

When the Pi is removed from ATP

Structure and full name of ATP

adenosine triphosphate

Mix with detergent

breaks down cell membrane releases cell contents into solution

Grind sample importance

breaks down cell walls

Add salt

breaks the hydrogen bonds between DNA and the water molecules

How is ATP formed rapidly?

by phosphorylation of ADP

Easily regenerated

can be recharged with energy

Add layer of alcohol

causes DNA to precipitate out of the solution

Water-soluble

energy-requiring processes happen in aqueous environments

Adenine and thymine

form 2 H bonds

Cytosine and guanine

form 3 H bonds

Bonds between phosphates

have intermediate energy large enough to be useful for cellular reactions but not so large that energy is wasted as heat

What are the names of the reactions involved in the interconversion of ATP and ADP?

hydrolysis (ATP to ADP and Pi) condensation (ADP and inorganic phosphate to ATP)

What type of reaction is this?

hydrolysis because water is used in the removal of the phosphate group

Purine

larger bases double carbon ring structure

What is the effect of pyrimidines always bonding to purines

maintains a constant distance between the DNA backbones so the polynucleotide chains are parallel

example of synthesis

making large molecules like proteins

Small

moves easily into, out of, and within cells

Structure of deoxyribose

one fewer oxygen atom

WHy do they not need to store large amounts of it?

phosphorylation is happening constantly in all living cells

example of movement

protein fibres in muscle cells that cause muscle contraction

Releases energy in small quantities

quantities are suitable to most cellular needs, so that energy is not wasted as heat

WHy is ATP ideally suited to its function as an energy storage molecule? 5

small (moves into/out of/ within cells) water-soluble (most cellular reactions happen in aqueous environments) contains bonds between phosphates with intermediate energy (large enough to be useful but not so large to be wasted as heat) releases energy in small quantities (suitable for most cellular needs but not wasted as heat) easily regenerated (can be recharged with energy)

Pyrimidine

smaller bases single carbon ring structure

What is the structure of DNA

sugar-phosphate backbone pairs of bases (AT or CG)

What are the 3 main types of activity for which cells require energy

synthesis transport movement

Define Phosphorylation

the addition of a phosphate group to a molecule

DNA molecule

the double helix composed of 2 antiparallel strands each strand is one chain of nucleotides (a polynucleotide)

what is special about the amounts of G and C, and T and A

they are the same