Lecture 8 - Catching Star Light Photosynthesis Part 1

Where does photosynthesis occur in plant cells?

chloroplast of mesophyll cells

What is the purpose of photosynthesis?

convert light energy to chemical energy

What is the role of the thylakoid membrane?

contains photosynthetic machinery, impermeable to most ions and molecules

What is the overall equation for photosynthesis?

h20 + co2 = ch2o + o2

Which chlorophyll pigments are found in thylakoid membranes?

chlorophyll a and b

Which wavelengths of light do chlorophyll a and b mainly absorb?

blue and red light

What do antenna systems do?

contain light absorbing molecules that capture light energy

What are the two photosystems?

photosytem 2, photosystem 1

What happens when a photosystem absorbs light?

light energy excites electrons

What is the reaction centre of Photosystem II called?

p680

What happens when light excites electrons in PSII?

electrons transferred to electron acceptor

What happens to plastoquinone (Q) when it accepts electrons?

reduced to qh2

How does linear electron flow help produce ATP?

builds proton gradient which drives atp synthase

How are electrons lost from PSII replaced?

water split, electrons replaced

What is the role of NADP⁺ reductase?

reduces nadp to nadph

What are electron holes?

gaps when electrons leave photosystems

hat do mitochondria and chloroplasts have in common?

use a proton gradient to drive atp synthesis

How does the proton gradient differ between mitochondria and chloroplasts?

mitochondria use proton gradient and electrical charge, chloroplasts use proton gradients because ions can pass

Which photosystem is involved in cyclic electron flow?

photosystem 1

What is the reaction centre of PSI called?

p700

What happens during cyclic electron flow?

electrons cycle through etc, building gradient used to make atp