Cell Bio Chapter 13

What is the most abundant biological macromolecule on Earth?

cellulose

Which of the following statements best describes how glucose is used by photoautotrophs?

Some glucose is used to power chemical reactions; some is used for biomass growth.

Magnesium is ideally suited for:

capturing light energy.

Porphyrin rings are chemical structures that:

are naturally occurring.

Which of the following organisms originally evolved the ability to photosynthesize?

cyanobacteria

Chloroplasts possess their own DNA, ribosomes, and other transcriptional and translational machinery.

True

Cyanobacteria and chloroplasts both possess thylakoids.

True

Which of the following possess a peptidoglycan layer?

cyanobacteria

Which of the following statements about carboxysomes and rubisco is true?

Chloroplasts do not possess carboxysomes, but they possess rubisco.

The components within photosystems that are responsible for capturing light energy are proteins.

False

To rearrange molecules of CO2 into molecules of glucose requires an input of energy.

True

The input of electrons required to convert CO2 into glucose during photosynthesis comes from:

H2O.

The chlorin group in a chlorophyll molecule contains an atom of ___ in its center.

magnesium

Wavelengths corresponding to ___ light are NOT absorbed by chlorophyll a.

green

When an electron within a pigment molecule absorbs photon energy, it immediately falls down to a lower orbit.

False

The energy from light photons travels through the photosystem until it eventually reaches a ___ pigment in the reaction center.

chlorophyll a

When the energy that originated from a photon of light reaches the reaction center, an electron from chlorophyll a in the reaction center is transferred to PQ.

True

The electron that was bumped off chlorophyll a in the reaction center is replaced by an electron from:

water

PQH2 moves through the thylakoid membrane and hands off its two electrons to cytochrome B6F.

True

When PQH2 hands off its electrons, the proton concentration in the thylakoid lumen:

increases.

The potential energy present within the high concentration of protons in the thylakoid lumen will be used by:

ATP synthase.

Which of the following electron carriers does NOT carry electrons after they are excited by photosystem I?

PQ

Part of the reason that the concentration of protons in the thylakoid lumen is high is because the volume of the thylakoid lumen is small.

True

The potential energy built up in the thylakoid lumen is best thought of as a build-up of atoms rather than a build-up of charge.

False

Which part of ATP synthase is responsible for combining ADP with Pi to produce ATP?

the head subunits

The ATP synthase drive shaft spins along with the turbine.

True

ATP synthase is powered by:

the flow of protons.

ATP synthase converts ___ energy into ___ energy and then into ___ energy.

electrical; mechanical; chemical

Photosynthesis Stage 2 occurs predominantly in the dark.

False

Which of the following exits the Calvin cycle?

G3P

During the Calvin cycle, the enzyme rubisco adds ___ to ribulose-1,5-bisphosphate.

CO2

What is the product of the Calvin cycle?

glyceraldehyde 3-phosphate

The product of the Calvin cycle is:

G3P

In plant cells, chloroplasts and mitochondria exist together in the same cell.

True