Question

multiple choice – part iii
highlight or circle the correct answer choice.

1. enzymes change their shape during a reaction

a. true
b. false

1. what do you call something that speeds up a reaction?

a. product
b. motor
c. catalyst
d. substrate

1. what happens if you put an enzyme in a temperature that is higher than its optimum temperature?

a. it dies
b. it denatures
c. it explodes
d. it works

1. what is the optimum ph for the pepsin shown on the graph?

a. 2
b. 9
c. 6
d. 7
(graph: pepsin, salivary amylase, alkaline phosphatase vs ph)

1. what is the substrate that catalase (the enzyme from our celery lab) breaks down?

a. oxygen
b. vinegar
c. glucose
d. hydrogen peroxide

1. what is a product that was created by the reaction in our celery lab?

a. oxygen
b. vinegar
c. glucose
d. hydrogen peroxide

short answer – part iv
write or draw a labeled diagram to answer the question.

macromolecule polymers are built by putting monomers together. would you use a decomposition reaction or a synthesis reaction to build a macromolecule? explain why.

Explanation:

Multiple Choice Answers:

1. a. true (Enzymes undergo conformational changes during catalysis, like induced fit model shows shape adjustment to substrate.)
2. c. catalyst (A catalyst increases reaction rate; enzymes are biological catalysts. Product is reaction result, motor is mechanical, substrate is reactant for enzyme.)
3. b. it denatures (High temperature disrupts enzyme's 3D structure (denaturation), losing active site. Enzymes aren't alive to "die", don't explode, and high temp above optimum reduces activity, doesn't make it work better.)
4. a. 2 (From the graph, pepsin's peak (optimum pH) is at pH 2, as it's a stomach enzyme working in acidic environment.)
5. d. hydrogen peroxide (Catalase enzyme breaks down hydrogen peroxide ($\ce{H_2O_2}$) into water and oxygen in the celery lab.)
6. a. oxygen (Catalase reaction: $\ce{2H_2O_2 ->[catalase] 2H_2O + O_2}$, so oxygen is a product.)

Short Answer:

To build a macromolecule (polymer) from monomers, a synthesis reaction (specifically dehydration synthesis) is used.

• A synthesis reaction involves combining smaller molecules (monomers) to form a larger molecule (polymer). In dehydration synthesis, monomers are linked by removing a water molecule (one monomer donates a -OH, another donates an -H, forming $\ce{H_2O}$ and a covalent bond between monomers).
• A decomposition reaction breaks larger molecules into smaller ones (opposite of building polymers). For example, hydrolysis (a type of decomposition) breaks polymers into monomers by adding water. Thus, to assemble monomers into a polymer, synthesis (dehydration synthesis) is required.

Multiple Choice Final Answers:

1. a. true
2. c. catalyst
3. b. it denatures
4. a. 2
5. d. hydrogen peroxide
6. a. oxygen

Short Answer Final Answer:

A synthesis reaction (dehydration synthesis) is used to build a macromolecule. This is because synthesis reactions combine smaller monomers into larger polymers, typically via dehydration synthesis (removing water to form covalent bonds between monomers). Decomposition reactions break molecules apart, so they cannot build polymers.

Answer:

• A synthesis reaction involves combining smaller molecules (monomers) to form a larger molecule (polymer). In dehydration synthesis, monomers are linked by removing a water molecule (one monomer donates a -OH, another donates an -H, forming $\ce{H_2O}$ and a covalent bond between monomers).
• A decomposition reaction breaks larger molecules into smaller ones (opposite of building polymers). For example, hydrolysis (a type of decomposition) breaks polymers into monomers by adding water. Thus, to assemble monomers into a polymer, synthesis (dehydration synthesis) is required.

Multiple Choice Final Answers:

1. a. true
2. c. catalyst
3. b. it denatures
4. a. 2
5. d. hydrogen peroxide
6. a. oxygen

Short Answer Final Answer:

A synthesis reaction (dehydration synthesis) is used to build a macromolecule. This is because synthesis reactions combine smaller monomers into larger polymers, typically via dehydration synthesis (removing water to form covalent bonds between monomers). Decomposition reactions break molecules apart, so they cannot build polymers.