Amino acids, nucleic acids, water & ATP

Question 1

What are amino acids?

Answer 1

Amino acids are the monomers from which proteins are made.

Question 2

What bond forms between two amino acids in a dipeptide?

Answer 2

A peptide bond forms between two amino acids.

Question 3

How are dipeptides formed?

Answer 3

Dipeptides are formed by a condensation reaction between two amino acids.

Question 4

What are polypeptides?

Answer 4

Polypeptides are chains formed by many amino acids joined together.

Question 5

What determines the primary structure of a protein?

Answer 5

The specific sequence and number of amino acids in the chain.

Question 6

What happens during the secondary structure of a protein?

Answer 6

The primary structure folds into a 3D shape using hydrogen bonds, forming an alpha-helix or beta-pleated sheet.

Question 7

What bonds are involved in the tertiary structure of proteins?

Answer 7

Disulfide bonds (strong), ionic bonds (weaker), and hydrogen bonds (easy to break).

Question 8

What is quaternary protein structure?

Answer 8

Two or more tertiary structures that come together, sometimes with prosthetic groups.

Question 9

What are examples of globular proteins?

Answer 9

Insulin and hemoglobin (soluble).

Question 10

What are examples of fibrous proteins?

Answer 10

Collagen and keratin (insoluble).

Question 11

What is an enzyme and what is its role?

Answer 11

Enzymes are globular proteins that act as biological catalysts, increasing the rate of chemical reactions.

Question 12

How do enzymes lower activation energy?

Answer 12

Enzymes allow the formation of enzyme-substrate complexes, lowering activation energy without being changed permanently.

Question 13

How do substrates bind to enzymes?

Answer 13

Substrates bind to the enzyme’s active site to form enzyme-substrate complexes.

Question 14

What is the lock and key hypothesis?

Answer 14

The enzyme’s active site has a specific shape that is complementary to the substrate.

Question 15

What is the induced fit model?

Answer 15

The enzyme changes its active site shape to better fit the substrate and improve the fit.

Question 16

How does temperature affect enzyme activity?

Answer 16

Temperature increases enzyme activity until it denatures at high temperatures, breaking bonds.

Question 17

What happens to enzyme activity at extreme pH?

Answer 17

Enzymes denature because bonds are broken permanently.

Question 18

What happens when substrate concentration increases?

Answer 18

Enzyme activity increases until all active sites are full, after which it plateaus.

Question 19

How does enzyme concentration affect reaction rate?

Answer 19

Enzyme activity increases with more enzymes but eventually becomes limited by substrate concentration.

Question 20

What is competitive enzyme inhibition?

Answer 20

Inhibitors bind to the enzyme’s active site, competing with the substrate due to a similar shape.

Question 21

What is noncompetitive enzyme inhibition?

Answer 21

Inhibitors bind to the enzyme at an allosteric site, altering the enzyme’s shape and making the substrate no longer complementary.

Question 22

What is the structure of a nucleotide?

Answer 22

A nucleotide consists of a phosphate group, a pentose sugar, and an organic base.

Question 23

What are the complementary base pairs in DNA?

Answer 23

Adenine pairs with thymine, and cytosine pairs with guanine via hydrogen bonds.

Question 24

What is the difference between DNA and RNA?

Answer 24

DNA has deoxyribose, thymine, and is double-stranded. RNA has ribose, uracil, and is single-stranded.

Question 25

What is the function of DNA?

Answer 25

DNA stores genetic information, protects it with base pairing, and allows for accurate replication.

Question 26

What is semi-conservative DNA replication?

Answer 26

DNA replicates by splitting into two strands, using each strand as a template to form new identical strands.

Question 27

How does DNA helicase help in replication?

Answer 27

DNA helicase breaks hydrogen bonds between bases, separating the strands.

Question 28

What is the role of DNA polymerase in replication?

Answer 28

DNA polymerase joins nucleotides together through condensation reactions, forming phosphodiester bonds.

Question 29

What makes water a polar molecule?

Answer 29

Covalent bonds between O and H cause a polar molecule, allowing it to dissolve other polar molecules.

Question 30

What bonds form between water molecules?

Answer 30

Hydrogen bonds form between water molecules.

Question 31

What are the unique properties of water?

Answer 31

Water is metabolite, adhesive, cohesive, a universal solvent, has a high specific heat capacity, and surface tension.

Question 32

What are the uses of ATP?

Answer 32

ATP is used for metabolic processes, movement, active transport, secretion, and molecule activation.

Question 33

What is the structure of ATP?

Answer 33

ATP consists of adenine, ribose, and three phosphate groups.

Question 34

How is ATP synthesized?

Answer 34

ATP is synthesized by the addition of inorganic phosphate to ADP using energy from respiration.

Question 35

Why is ATP a good energy source?

Answer 35

ATP releases energy in small, manageable amounts and has unstable phosphate bonds with low activation energy.