Chapter 5 Flashcards by maha rahama

Photosynthesis

light energy is used to make glucose

How well did you know this?

Not at all

Perfectly

Solar energy is converted into chemical energy

bc energy is stored in chemical bonds

How well did you know this?

Not at all

Perfectly

Photosynthesis is carried out by

all organisms in plant kingdom and algae in protista kingdom

How well did you know this?

Not at all

Perfectly

Photosynthesis equation

6CO2+ 12H20 → C6H12O6 + 6H20 + 6O2

Carbon dioxide + water → sugar + water + oxygen

How well did you know this?

Not at all

Perfectly

What type of reaction is photosynthesis?

This is a reduction reaction because carbon in co2 is gaining electrons from hydrogen in water (reduction→ the gain of electrons or protons)

How well did you know this?

Not at all

Perfectly

Autotrophs

organisms that make their own food

How well did you know this?

Not at all

Perfectly

Chloroplasts are

enclosed by a double membrane and contains grana (consisting of layers of membranes called thylakoids)

How well did you know this?

Not at all

Perfectly

What happens in the grana?

light-dependent reactions occur

How well did you know this?

Not at all

Perfectly

What happens in the stoma?

the Calvin cycle (light independent reactions occur)

How well did you know this?

Not at all

Perfectly

When light strikes an object, it can be

reflected, transmitted or absorbed

How well did you know this?

Not at all

Perfectly

Something that appears red

reflects red light and absorbs all other colors of light

How well did you know this?

Not at all

Perfectly

What do photosynthetic pigments do?

absorb light energy and use it to carry out photosynthesis

How well did you know this?

Not at all

Perfectly

Pigments

substances that absorb light in the visible spectrum

How well did you know this?

Not at all

Perfectly

Different pigments absorb

light of different wavelengths

How well did you know this?

Not at all

Perfectly

What can participate directly in light-dependent reactions?

Only chlorophyll (green photosynthetic pigment) can participate directly in light-dependent reactions

How well did you know this?

Not at all

Perfectly

What assists in photosynthesis?

Other pigments called antennae (or accessory pigments )

How well did you know this?

Not at all

Perfectly

How do antennae assist in photosynthesis?

by capturing and passing on photons of light to chlorophyll a and thus expand the range of light that can be used to produce sugar

How well did you know this?

Not at all

Perfectly

Accessory pigments include

chlorophyll b, carotenoids, and phycobilins

How well did you know this?

Not at all

Perfectly

Chlorophyll b

green, absorbs all the other wavelengths of light besides green

How well did you know this?

Not at all

Perfectly

Carotenoids

yellow, orange, and red pigments and are responsible for the color of carrots

How well did you know this?

Not at all

Perfectly

Phycoblins

red pigments and are found in red algae that live deep in the ocean where there is very little light

How well did you know this?

Not at all

Perfectly

Red/Blue are

Yellow/Orange are

absorbed

reflected

How well did you know this?

Not at all

Perfectly

Only light that is absorbed can be

used to power the making of sugar

How well did you know this?

Not at all

Perfectly

2 main processes of photosynthesis are

light-dependent reactions (light reactions) and light independent reactions

How well did you know this?

Not at all

Perfectly

Both reactions only occur when

there is light

Function of light dependent reactions is to

produce energy (atp) and protons for the light independent reactions.

Function of light independent reactions

is to make sugar (pgal)

Light dependent reactions occur in the

grana of chloroplasts within specialized membranes called thylakoids

In these thylakoids are 100s of

light-absorbing complexed called photosystems

Each photosystem consists of

chlorophyll a and the accessory pigments, chlorophyll b and carotenoids

1 of the main results of light dependent reactions is that

large amounts of ATP are produced in chloroplasts that same way as cellular respiration in mitochondria by ETC and chemiosmosis

Flow of light-dependent reactions (in detail)

1. Chlorophyll in grana absorb light 2. Electrons become energized and escape from chlorophyll molecules into ETC 3. Energy from these energized electrons pumps protons across thylakoid membrane 4. Creates proton gradient 5. Potential energy stored in this proton is converted into ATP as protons flow through and ATP synthetase channel

Flow of light-dependent reactions (simple)

Light→chlorophyll→energized electrons →ETC →proton gradient→ atp synthetase →atp

Where does water have a role in these reactions?

Water breaks down by a process called photolysis into electrons, protons, and oxygen atoms

Water's Role: | Electrons

Electrons replace those lost by chlorophyll in the light dependent reaction

Water's Role: | Protons

Protons pass through ATP synthetase channel and get carried by NADP to stroma for light independent reaction

Water's Role: | Oxygen

Oxygen is released into the atmosphere as a waste product which is the source of oxygen in the atmosphere

In short, light dependent reactions

produce atp, provide protons to the calvin cycle in light independent reactions

Sugar is produced during the

calvin cycle of the light-independent reactions

Light independent reactions

Reactions occur in stroma, function is to produce sugar or pgal

In light-independent reactions,

CO2 (which plant takes in through leaves) combines with protons and electrons carried from light-dependent reactions by NADP to produce sugar

Equation of light-independent process

CO2+H^+ (protons) + electrons = PGAL

Carbon Fixation

incorporation of CO2 into a sugar molecule

Light Independent reactions occur

in cyclical process known as calvin cycle

Large amounts of ATP are required

to keep the calvin cycle running

All necessary ATP is produced during

light dependent reactions

Essence of Light-Independent reactions

- Take place in stroma - Pgal or phosphoglyceraldehyde, a 3-carbon sugar C(H20)n is produced - All important enzyme require for calvin cycle is rubisco (ribulose biphosphate_ - Uses large amts of atp

Differences between cellular respiration and photosynthesis: | Occurs:

CR: occurs all the time PS: occurs only in light

Differences between cellular respiration and photosynthesis: | redox

CR: oxidation reaction PS: reduction reaction

Differences between cellular respiration and photosynthesis: | relies on

both rely on ETC to produce proton gradient

Differences between cellular respiration and photosynthesis: | requires:

both require O2 and release CO2

Differences between cellular respiration and photosynthesis: | proton carrier is:

CR: NAD is proton carrier PS: NADP is proton carrier

Differences between cellular respiration and photosynthesis: | ATP is produced by:

ATP synthetase

Differences between cellular respiration and photosynthesis: | contains which cycle?

CR: contains cycle process, krebs cycle PS: contains cyclincal process, calvin cycle

Palisade layer consists of

tightly packed cells that contain chloroplasts

Palisade layer is where

majority of photosynthesis occurs

Spongy mesophyll contains

chloroplasts and also carries out photosynthesis

Cells in spongy mesophyll are

less tightly packed and surrounded by air spaces which allow for exchange of O, CO2, and water vapor

Epidermis layer

is clear, does not carry out photosynthesis

The epidermis layer is

waterproof layer of cutin that minimizes excessive water loss

Guard cells

controls opening and closing of stomates which allows for exchange of gasses with minimum water loss