Lecture 4

Question 1

Fermentation

Answer 1

a metabolic pathway that changes pyruvate
Energy required is supplied by the conversion of NADH to NAD+.
By generating NAD+, it allows glycolysis to continue in the absence of oxygen.

Question 1

Where does fermentation occurs in eukaryote and prokaryote?

Answer 1

Occurs in the cytosol for both eukaryotic and prokaryotic.

Question 2

Fermentation in plants produces

Answer 2

ethanol

Question 3

Fermentation in humans produces

Answer 3

Lactic acid

Question 4

Wavelenght

Answer 4

the distance between the top of one wave to the top of the other wave

Question 5

Frequency

Answer 5

The number of waves that passed at a certain point during a certain point.

Question 6

Electromagnetic waves:

Answer 6

waves in the electromagnetic field. Also called electromagnetic radiation. Occurs in packets called photons.

Question 7

What is the wavelength or frequency correlated with?

Answer 7

The wavelength or frequency is correlated with the energy of the photon.

Question 8

High wavelength =

Answer 8

low frequency = low energy photon.

Question 9

Low wavelength =

Answer 9

Low wavelength = high frequency = high energy photon. (ex: gamma rays = dangerous for us).

Question 10

Pigment

Answer 10

a molecule that absorbs visible light. Each pigment absorbs only light of certain wavelengths.
When a pigment absorbs light, it absorbs the energy from the photons.
(ex: black is very warm because absorbs wavelengths = all photons = high energy)

Question 11

Photosynthesis:

Answer 11

the use of light energy to synthesize carbohydrates out of CO2 and H2O.

Question 12

What are the two stages of photosynthesis?

Answer 12

Two stages:
Light reactions (light-dependant reaction): require pigments (play important role) = chlorophyll a (most important pigment) and a bunch of accessory pigments. (chlorophyll a does not absorb green = that’s why it looks green).
Calvin cycle (dark/light-indep reactions):

Question 13

Where do light reactions occur?

Answer 13

Light reactions occur in the membrane of thylakoids (found in chloroplast in eukaryotes).

Question 14

What is the photosystem 1

Answer 14

a cluster of pigments, around a reaction center that includes a chlorophyll a inside.

Photon is captured by pigments and chlorophyll a absorbs energy of photon and the energy ends up in a pair of electrons in reaction center. If the other pigments get the photon (pigments might absorb other wavelengths), they will send energy to reaction center.

This is where we convert light energy to energize a pair of electron.
The point is to generate the high energy electron.

Light energy is absorbed by Photo System 1 that pass along the chain as energized electrons and turn NADP+ to NADPH.

Question 15

Photosystem 2

Answer 15

cluster of pigment surrounding a reaction center. Absorb light from photon and energize electron that are passed along the chain leaving energy that lets H+ pass through the membrane (like cel resp).

It takes the energy from photon to steal electron from water molecule (breaks a covalent bond). The rest becomes O + 2H+. The rest of electron goes to photosystem 1 again and continues (is energized again by photon

gives NDPH O + 2H+
ATP synthase is also found in thylakoid membrane. It can use the flow of H+ to create ATP. That’s why you need the membrane.