B4 - analyse the structure and function of nucleic acids

Recognize structural diagrams of: DNA, RNA, ATP

List the functions of DNA and RNA Describe the structure of DNA in terms of

nucleotides, base pairing, double helix Compare the structure of DNA and RNA Relate the structure of ATP to its function

C, H, O, N, P

Nucleotides - have 3 parts:

• 5-carbon sugar• Phosphate group

(PO4)• Nitrogenous base

(ring structure, contains C,N,H)

Purine bases (2 rings):

Adenine GuaninePyrimidine bases (1

ring): Cytosine Thymine Uracil

Nucleotides join together in long chains called nucleic acids

The two important nucleic acids in cells are DNA and RNA

• Double stranded• Sugar is deoxyribose• 4 nitrogen bases:

adenine, thymine, cytosine and guanine (A,T,C,G)

• Complementary base pairing - Hydrogen bonds form between A & T, C &G

• The two strands are “antiparallel” – oriented in opposite directions

The DNA molecule forms a double helix (“twisted ladder”)

“rungs” are base pairs, connected by hydrogen bonds

Sides are alternating sugar – phosphate groups

Single stranded Sugar is ribose 4 nitrogen bases - adenine,

uracil, cytosine, guanine (A,U,C,G)

DNA stores genetic material in the nucleus (instructions for protein synthesis)

RNA functions in protein synthesis (decoding DNA) in the nucleus and cytoplasm (ribosomes)

Together they determine the primary structure of all proteins made in the body

ATP (adenosine triphosphate) - a special nucleotide found in all cells

Adenine base, ribose, 3 phosphate groups

ATP is the “energy molecule” produced during cellular respiration used whenever energy is required

ATP contains high energy bonds between the phosphate groups

Energy is released when the bonds are broken

ADP is produced when 1 phosphate is removed

ATP + H2O ↔ ADP + phosphate + energy This energy can be used for many different cell / body functions (examples?) ATP / ADP are continuously recycled in cells