2.8 Nucleic Acids + ATP

Question 1

what are the two types of nucleic acids

Answer 1

DNA (deoxyribonucleic acid) and RNA (ribonucleic acid)

Question 2

why is DNAimportant

Answer 2

stores genetic information in cell and organism

when cell replicates and transmits information when the cell copies itself as well as when the organism reproduces

Question 3

what are nucleotides

Answer 3

molecular complex of three sub units; phosphate (phosphoric acid), a pentode sugar and a nitrogen containing base

Question 4

what do the nucleotides in DNA and RNA contain

Answer 4

DNA: sugar deoxyribose
RNA: sugar ribose

Question 5

what are the four types of bases in DNA and RNA

Answer 5

DNA : adenine + thymine
cytosine + guanine

RNA: adenine + uracil, cytosine + guanine

Question 6

why are bases called bases

Answer 6

their presence raises the pH of a solution
two rings: adenine or guanine
one ring: thymine or cytosine

Question 7

what is a strand

Answer 7

nucleotides that form a linear molecule which has a backbone of alternating phosphates and sugars with bases projecting to one side of the backbone

Question 8

what is the human genome

Answer 8

human bases in DNA that have a specific order which improved genetic counselling, gene therapy, and medicines that cause human illnesses

Question 9

describe the structure of DNA

Answer 9

double helix: two strands twisted about each other held together by hydrogen bonds between bases
sides of ladder: alternating phosphate and sugar molecules
rungs of ladder: bases (adenine + thymine, cytosine + guanine)

Question 10

why is base pairing in DNA important

Answer 10

allows DNA to replicate that ensures sequence of base will remain the same
base sequence in specific sections of DNA contain a code that specified the sequence of amino acids in the proteins of the cell

Question 11

describe the structure of RNA

Answer 11

single stranded; formed by base pairing w one DNA strand

Question 12

describe one type of RNA

Answer 12

mRNA (messenger RNA) carries info from DNA strand to ribosome where translated into sequence of amino acid specified by DNA

Question 13

what is ATP

Answer 13

adenosine triphosphate (immediate source of energy)
universal “currency” is the cells in living systems used for
-chemical work: energy supply that synthesize macromolecules (anabolism) that make up cell
-transport work: energy supply to pump substances across plasma membrane
-mechanical work: energy supply for muscles to contract, folks and flagella to beat, chromosomes to move

Question 14

describe the structure of ATP

Answer 14

nucleotide composed of adenine (nitrogen containing base), 5 carbon sugar ribose, 3 phosphate groups (triphosphate)

Question 15

where is the energy stored in ATP

Answer 15

chemical bonds of phosphates

Question 16

describe the last two phosphate bonds in ATP

Answer 16

• unstable, easily broken

- usually hydrolyzed in cells leaving ADP and a molecule of inorganic phosphate

Question 17

describe the chemical, transportational, mechanical work of ATP

Answer 17

chemical: supplies energy to synthesize macromolecules (anabolism) that make up cell
transport: supplies energy needed to pump substances across plasma membrane
mechanical: muscle contraction, cilia flagella to beat, chromosomes to move

IMMEDIATE SOURCE OF ENERGY

Question 18

describe the exergonic reaction for ATP

Answer 18

• realeases previously stored energy allowing change in free energy to do work and drive other processes
• protein synthesis, nerve conduction, muscle contraction

ATP -> ADP + P

Question 19

describe the endergonic reaction

Answer 19

-creation of ATP from ADP + P requires input of energy from
other sources
-glucose breaking down in cellular respiration so energy of glucose is converted to that of ATP molecules in mitochondria
-only 39% is ATP, rest lost as heat