Active Transport and Obtaining Energy

Question 1

Hypotonic

Answer 1

Low solute, lots of solvent

Question 2

Hypertonic

Answer 2

High solute, low solvent

Question 3

Isotonic

Answer 3

Equal parts solute and solvent.

Question 4

What is Endocytosis?

Answer 4

When cells take in material.

Question 5

Three types of Endocytosis

Answer 5

Phagocytosis: Engulfing a particle and surrounding it with a vesible
Pinocytosis: A cell takes in fluid that contains dissolved particles and surrounds it with a vesicle.
Receptor Mediated Endocytosis: The cell has receptors (that looks like a virus’s) that attach to particles and drag them in.

Question 6

Explain Exocytosis

Answer 6

Particles in a vesicle move to the membrane of the cell. The vesicle becomes part of the membrane and makes an opening that releases the particles to the extracellular fluid.

Question 7

What is the purpose of the sodium-potassium pump?

Answer 7

Maintains the resting membrane potential: the difference between the voltage inside and outside of the cell (this depends on the type of cell). Most cells are more negative inside than outside.

Question 8

How does a sodium potassium pump maintain a membrane’s resting potential?

Answer 8

3Na+ is pushed to the outside of the cell and 2K+ are brought inside the cell. This cycle makes the inside of the cell more negative.

Through active transport: ATP is used against a con. gradient.

Question 9

First 4 steps of Light Dependent Reactions (Ending with ATP synthase generating energy)

Answer 9

1. Light is absorbed by the chlorophyll, its electrons become excited.
2. Two electrons leave and go down the ETC. Electrons from the water are used to replace them, so water breaks down into H+ and 02
3. As the 2 electrons go down the chain, they help pump H+ into the thylakoid.
4. The H+ accumulates inside and rushes out through ATP synthase (a generator) which makes some ATP.

Question 10

The second stage (3 steps) of light dependent reactions (ending with NADPH).

Starting after ATP synthase makes some energy

Answer 10

5. The two electrons reach photosystem 1, where they are excited by light again.
6. The 2 electrons travel through a shorter ETC, where they as well as hydrogen are picked up by NADP+.
7. NADP+ becomes NADPH: an electron carrier that will carry the electrons to the next stage.

Question 11

Phase 1 (Carbon Fixation) of the calvin cycle (2 steps)

Answer 11

1. An enzyme rubisco takes CO2 from air, combines it with RuBP (A 5 carbon compound) to make a 6 carbon compound.
2. The 6 carbon compound splits in half.

Question 12

Reduction Phase (Phase 2) of the Calvin Cycle. (2 steps)

Answer 12

1. ATP from light-dependent reactions creates an intermediate compound.
2. The intermediate compound is reduced (gains electrons and hydrogen ions) from NADPH to make G3P (key product).

Question 13

Regeneration (Phase 3) of the calvin cycle (2 steps).

Answer 13

1. 2G3P are removed from the cycle (2G3P together make glucose)
2. Remaining G3P is turned back into RuBP (using energy) so the cycle can continue from phase 1.

Question 14

What happens during phase 1 (Glycolosis) of cellular respiration?

Answer 14

1. In the cytoplasm, glucose is converted into 2 pyruvates (a more usable form). Net Yield: 2 pyruvate, 2 ATP, 2NADH

Question 15

2 Steps of the Intermediate phase in cellular respiration.

Answer 15

1. Pyruvate is taken to the mitochondrial matrix via active transport.
2. Pyruvate is oxidized into 2 acetyl CoA, which also release CO2 and 2NADH

Question 16

Input, 3 outputs, and waste product of the Kreb’s cycle (Phase 2 of cellular respiration)

Where does this occur?

Answer 16

1. Acetyl CoA (input)
2. 2ATP, 6NADH, 2FADH2 (outputs)
3. CO2 (waste)

We are still in the mitochondrial matrix!

Question 17

3 steps of the ETC (3rd phase of cellular respiration).

Answer 17

1. e- from NADH and FADH2 are moved along the ETC, helping to pump hydrogen out into the intermembrane space.
2. Oxygen is the final acceptor of the electrons, making H20
3. Hydrogen rushes back into the matrix through ATP synthase, makes 20-something ATP!