Photosynthesis Lecture Review

Fill-in-the-blank flashcards covering definitions, structures, processes, and limiting factors related to photosynthesis.

Photosynthesis is the process by which organisms use _ to produce glucose from CO₂ and H₂O.

sunlight energy

The word equation for photosynthesis is: carbon dioxide + water → _ + oxygen.

glucose

During photosynthesis, _ gas is released as a by-product.

oxygen

Conversion of light energy to chemical energy is associated with the green pigment __.

chlorophyll

All photosynthetic organisms possess the primary pigment chlorophyll __.

a

Accessory pigments such as chlorophyll b, xanthophylls and __ absorb wavelengths chlorophyll a does not.

carotenoids

Chlorophyll a absorbs mainly __ and red wavelengths, but little green-yellow light.

violet-blue

Every chlorophyll molecule has a lipid-soluble hydrocarbon tail and a flat hydrophilic head with a central _ ion.

magnesium

A leaf can be viewed as a __ crammed full of photosynthetic cells.

solar collector

Water is transported from roots to leaves through specialized tubes called __ vessels.

xylem

Gas exchange in leaves occurs through tiny pores called __, each flanked by two guard cells.

stomata

The waxy __ prevents uncontrolled gas passage through the leaf surface.

cuticle

The flattened sacs where photosynthesis occurs are called __; stacks of these form grana.

thylakoids

Spaces between grana inside chloroplasts are filled with the __.

stroma

Unlike mitochondria (two membranes), a chloroplast possesses __ membrane systems.

three

Light-dependent reactions occur in the grana and generate ATP and _ by using light energy.

NADPH

Photolysis splits water: 2H₂O → 4H⁺ + _ + 4e⁻.

O₂ (oxygen)

In the light-dependent reactions, NADP⁺ is __ to form NADPH.

reduced

Light-independent reactions (Calvin cycle) take place in the __ of the chloroplast.

stroma

Photosystem II has a reaction-centre pigment that absorbs maximally at _ nm.

680

Photosystem I absorbs most efficiently at _ nm.

700

The zig-zag electron energy diagram of photosynthesis is commonly called the _ scheme.

Z

Non-cyclic phosphorylation produces both ATP and _, passing electrons from water to NADP⁺.

NADPH

A proton electrochemical gradient across the thylakoid membrane drives ATP synthesis via __.

chemiosmosis

Cyclic phosphorylation involves only PSI and produces extra _ but no NADPH.

ATP

Carbon dioxide is first fixed when it combines with the 5-carbon sugar __ in the Calvin cycle.

ribulose-1,5-bisphosphate (RuBP)

Two molecules of glyceraldehyde-3-phosphate (GALP) exit the Calvin cycle to form one molecule of __.

glucose

Light intensity, CO₂ concentration, and __ are the three main limiting factors of photosynthesis.

temperature

glucose

Simple sugar produced during photosynthesis, formed from two molecules of glyceraldehyde-3-phosphate.