Nucleic Acids & ATP

Question 1

What are the monomers of nucleic acids?

Answer 1

Nucleotides

Question 2

What are the polymers of nucleic acids?

Answer 2

Polynucleotides

Question 3

What elements are nucleic acids made up of?

Answer 3

Carbon, hydrogen, oxygen, nitrogen and phosphorus

Question 4

What is the structure of nucleotides?

Answer 4

Phosphate group, Penrose sugar, nitrogenous base

Question 5

What bonds are formed between nucleotides?

Answer 5

Phosphodiester

Question 6

What is the structure of DNA?

Answer 6

• polymer of nucleotides
• each nucleotide formed from deoxyribose, a phosphate group and a nitrogenous base
• phosphodiester bonds between nucleotides
• double helix / 2 strands held by hydrogen bonds
• hydrogen bonds between complementary bases (adenine and thymine, cytosine and guanine)

Question 7

Explain the structure of DNA

Answer 7

• long + helical = compact, can store lots of info
• composed of sequence of bases = codes for specific amino acid sequences
• double stranded = protects bases, increased stability, each strand acts as template for replication
• sugar phosphate backbone = strength
• weak hydrogen bonds easily broken for replication
• many hydrogen bonds = stability

Question 8

What is the differences between RNA and DNA?

Answer 8

• DNA: deoxyribose, RNA: ribose
• RNA: uracil replaces thymine
• DNA: longer, RNA: shorter
• DNA: double stranded, RNA: single stranded

Question 9

What are the similarities between DNA and RNA?

Answer 9

• both polynucleotides
• both contain phosphate group, pentose sugar and nitrogenous base
• both form phosphodiester bonds through condensation reaction

Question 10

How many hydrogen bonds are there between complementary bases?

Answer 10

• CG: 3
• AT: 2

Question 11

What are the 3 types of RNA?

Answer 11

• mRNA: composed of codons
• tRNA: composed of anticodons
• rRNA: forms ribosomes and proteins

Question 12

Describe the process of DNA replication

Answer 12

• DNA helicase breaks hydrogen bonds and separates strands
• both strands act as templates
• complementary base pairing with exposed bases
• DNA polymerase joins adjacent nucleotides together, forming phosphodiester bonds
• semi conservative replication

Question 13

What is semi-conservative replication?

Answer 13

New molecules of DNA are made up of one old strand and one new strand

Question 14

What does ATP stand for?

Answer 14

Adenosine triphosphate

Question 15

What is ATP?

Answer 15

An immediate source of energy for biological processes

Question 16

What is the structure of ATP?

Answer 16

• Adenine
• Ribose
• 3 phosphate groups

Question 17

What is phosphorylation?

Answer 17

ADP + P —> ATP
- phosphate and energy added
- uses enzyme ATP synthase

Question 18

What is dephosphorylation?

Answer 18

ATP —> ADP + P
- phosphate removed
- energy released
- uses enzyme ATP Hydrolase

Question 19

How can ATP transfer energy to different compounds?

Answer 19

• phosphate released during hydrolysis of ATP (dephosphorylation) can be bonded to compounds to make them less stable and more reactive

Question 20

Name the properties of ATP

Answer 20

• releases small manageable amounts of energy so less energy wasted
• small + soluble so can move easily and readily around cytoplasm (same as glucose)
• only one bond broken to release energy immediately (glucose needs several bonds to be broken)
• can transfer energy to another molecule by transferring phosphate group (glucose cannot do this)
• can’t pass out of cell = immediate supply of energy (glucose can)

Question 21

What are the key uses of ATP in cells?

Answer 21

• metabolic processes
• movement
• active transport (energy used to change shape of carrier proteins)
• secretion (needed to form lysosomes)
• activation of molecules (phosphorylation makes molecules more reactive)