Here’s a full simple answer guide for you:

Part 2: Making Yogurt

1. What process is being demonstrated?

→ This is enzymatic hydrolysis (breaking down lactose with the help of an enzyme called lactase).

Sub-questions:

a. What type of reaction is this?

→ Hydrolysis reaction (breaking a bond using water).

Also, it is a catabolic reaction (breaking a big molecule into smaller ones).

b. Does the reaction require or release energy?

→ It releases energy (breaking bonds usually releases energy).

c. What type of biomolecule are lactose, glucose, and galactose?

→ They are carbohydrates (specifically sugars).

d. What type of biomolecule is lactase? What is it doing?

→ Lactase is a protein (specifically an enzyme).

It speeds up the breakdown of lactose into glucose and galactose.

e. What key reactant is missing?

→ Water (H₂O).

In hydrolysis, water must be added to break the bond.

Part 3: Out in the Arctic

1. What adaptations would you expect in the cell membranes of bacteria living below 0°C? Why?

→ Bacteria will have more unsaturated fatty acid tails in their phospholipids.

Why? Unsaturated fats have kinks (bends) that keep membranes fluid and prevent freezing in cold temperatures.

2. What changes would you expect in their DNA? Why?

→ They may have more A-T pairs instead of G-C pairs.

Why? A-T pairs have fewer hydrogen bonds (only 2), which helps DNA open more easily in cold environments (making replication and transcription easier when it’s cold).