Biology 1801 Test 3- John Walker (AppState)

Total radiant energy hitting earth from sun/day ≈

1 million Hiroshima A-bombs

One factor that has allowed life to evolve & thrive on earth is the abundance of _______ _______!

free energy

What major groups can photosynthesize?

(algae/protists, plants, bacteria)

Photosynthesis is not universal to _____ _____

all cells

Respiration?

A metabolic process wherein, the living cells of an organism obtains energy (in the form of ATP) by taking in oxygen and liberating carbon dioxide from the oxidation of complex organic substances.

Which groups of organisms conduct photosynthesis?

Plants, Protists, Bacteria

___________ is the use of sunlight to manufacture carbohydrates

Photosynthesis

Organisms that make organic molecules from inorganic ones are __________ ("self-feeders")

autotrophs

___________ ("different-feeders") must consume organic molecules

Heterotrophs

____________ converts electromagnetic energy to chemical energy

Photosynthesis

Photosynthesis requires?

1. Sunlight, carbon dioxide, and water
2. Produces oxygen as a by-product

What is oxidized?

Electrons have been pulled closer to the hydrogen
idk

What is reduced?

Electrons have been pulled closer to the carbon
idk

Photosynthesis in Plants?

Chloroplasts, Chlorophyll, Mesophyll & mesophyll cells, Stomata

Chloroplasts?

organelles in plants and algae that carry out photosynthesis. Endosymbiosis theory origin of this organelle (DNA, Binary fission)

Chlorophyll? and where it is located

main pigment (green) and is located in the chloroplast

Stomata?

carbon dioxide enters and oxygen exits leaf

_________ from atmosphere goes in through stomata

CO2

Stomata?

Pores that let CO2 come in

The source of CO2 used in photosynthesis is?

the atmosphere

Photosynthesis consists of two sets of reactions

1. The light-dependent reactions produce O2, ATP, NADPH
2. The Calvin cycle reactions produce sugar from CO2

The light dependent reactions and Calvin cycle reactions react where?

The light dependent reactions take place in the Thykoid membranes and the Calvin cycle reactions take place in the Stroma

Photosynthetic ___________ are located in the ___________ membranes

pigments, thylakoid

Most common pigment in thylakoids = __________ and reflects/absorbs what lights?

chlorophyll, and reflects green light and absorbs red and blue light

True or False: Is the chlorophyll responsible for the green color in plants

True

_________ ________ is the electromagnetic radiation that humans can see

Visible light

_________ wavelengths have more energy than longer wavelengths

Shorter

There are two major classes of pigment in plants:

1. The chlorophylls (chlorophyll a and chlorophyll b) that absorb red and blue light and reflect and transmit green light
2. The carotenoids absorb blue and green light and reflect and transmit yellow, orange, and red light

What light color has the highest energy?

Blue light

What light color has the lowest energy?

Red Light

A plant appears green because?

Chlorophyll absorbs red and blue light, and green light is reflected by chlorophyll.

Each pigment has an __________ __________

absorption spectrum

Produces the _______ __________ (rate of photosynthesis at each wavelength)

action spectrum

______ and _______ are the most effective at driving photosynthesis

blue and red photons

Carotenoids _______ the range of wavelengths that can drive photosynthesis

extend

Chlorophyll & accessory pigments have _______ consisting of ring structures that can absorb light energy

"heads"

When Light Is Absorbed, Electrons Enter an Excited State?

1. Chlorophyll can absorb red or blue photons
2. Red photons bump an electron up one energy level
3. Blue photons bump an electron up two energy levels
4. Green photons are intermediate, so are not absorbed

Exam!!! Energy (not the electrons but the excitement) can be transferred to nearby molecules is what?

Resonance Energy Transfer

A photosystem consists of two major elements?

1. An antenna complex- Is composed of 200-300 chlorophyll and accessory pigment molecules
2. A reaction center- Energy is transferred from one molecule to the next until it reaches the reaction center (by resonance)

__ finally transferred to a specialized chlorophyll molecule

E

Transfers an excited electron to an electron acceptor, 2 ways?

1. Redox
2. Transformed to chemical E

Which comes first (photosystem I or photosystem II)

Photosystem II

How does the photosystem II work?

1. Excited electrons passed to ETC
2. ETC pumps Protons into thylakoid lumen Drives ATP Synthase
3. Reaction center splits water (oxidized) Generates O2
4. Replaces electrons in reaction center

Oxidation of water yields oxygen gas (This is the only protein complex that can oxidize water into atmosphere)

Manganese cluster:

How does the photosystem I work?

1. Electrons from electronic transport chain re-excited
2. Passed to NADP+ reductase
3. NADP+ is reduced to form NADPH Terminal electron acceptor (end of electronic transport chain)

The __ _________ is a model of how photosystems I and II interact
PS II energy pumps protons, produces ATP
PS I energy excites electrons to produce NADPH

Z scheme

Since electrons pass from water to NADP+ in a linear fashion, it is called _________ ________ _______

noncyclic electron flow

________ __________ ________ also occurs in green algae and land plants and increases ATP

Cyclic electron flow

ATP and NADPH are produced by photosystems I and II in the?

stroma

What is used to drive Calvin cycle in stroma

Energy

Carbon fixation?

add inorganic carbon to an organic compound

Can the Calvin Cycle occur in the dark? Yes or No?

Yes

The Calvin cycle has three phases:

1. Fixation
2. Reduction
3. ​Regeneration

What is the output of the Calvin cycle

glyceraldehyde 3-phosphate (G3P)

Fixation?

CO2 attached to a five-carbon compound called ribulose bisphosphate (RuBP - 5C + 1CO2)

Reduction?

The 3PGA are phosphorylated by ATP and reduced by NADPH

Regeneration?

The remaining G3P is used in reactions that use ATP to regenerate RuBP

The CO2-fixing enzyme is ________ and thought to be the most abundant enzyme on earth

Rubisco

What does O2 fixation cause?

Photorespiration

What competes at rubisco's active sites

CO2 & O2

Where did all the oxygen come from in the atmosphere?

The photosystems

_______________ consumes oxygen, ATP, and releases fixed CO2

Photorespiration

Rate _________ when concentration of CO2 is ________ and O2 is higher

increases, lower

______ stomata allow CO2 to diffuse into the leaf and O2 to diffuse out and lose H2O in the process

Open

When conditions are hot and dry, _________ must close to prevent evaporation of water in this process what builds up and what drops

stomata, O2, and CO2

C4 plants, such as sugarcane and maize, use a different enzyme to initially fix CO2 and form what?

four-carbon compound (malate)

What is (CAM)

Crassulacean acid metabolism

Why does the stomata open at night and what happens when the stomata is closed during the day?

Fixation of CO2, and releases CO2 to be able to run the Calvin cycle

Both ___ and _____ pathways function to concentrate CO2 to drive the Calvin cycle

C4, CAM

Because energy is required, ___ plants are most efficient in normal conditions

C3

CO2 is realsed in what?

bundled sheath cells

What does G3P make?

Sugar (glucose)

All __________ use respiration

organisms

Which type of organisms carry out cellular respiration?

All organisms use cellular respiration.

Glucose is reduced or oxidized?

Oxidized

Oxygen is oxidized or reduced?

Reduced

In cellular respiration which molecule is oxidized?

Glucose

Are involved in the synthesis, modification, and breakdown of several types of cellular molecules and contain their own DNA, divide by binary fission

Intermembrane space and mitochondrial matrix

Cellular respiration is a set of four processes?

1. glycolysis- glucose broken down into two pyruvate
2. pyruvate processing- pyruvate is oxidized to form acetyl
3. citric acid cycle- acetyl is oxidized to fully CO2
4. electron transport and oxidative phosphorylation- ETC produces proton gradient that is used to make ATP

There are two phases of glycolysis

1. The energy investment phase- uses 2 ATP's
2. The energy payoff phase- produces 4 ATP and 2 NADH

Overview of Cellular Respiration

Energy Investment Phase

Energy Payoff Phase

What is substrate level phosphorylation

When a phosphoryl group is transferred from a substrate to ADP or GDP to form ATP or GTP, coupled with the release of free energy.

Chemiosmotic

The process of moving ions to the other side of a biological membrane, and as a result, an electrochemical gradient is generated. This can then be used to drive ATP synthesis.

There is feedback inhibition of ___________ by ATP

Glycolysis

____________ produced during glycolysis is transported into mitochondrial matrix (cytosol in prokaryotes)

Pyruvate

___________ ________ __________ of pyruvate dehydrogenase occurs when products of glycolysis and pyruvate processing are high

Inhibitory allosteric phosphorylation

In the citric acid cycle, each acetyl CoA (2C) from pyruvate processing is completely oxidized into _______ _____

two CO2

In Oxidizing Acetyl CoA to CO2 potential energy is used to

1. Reduce three NAD+ to NADH
2. Reduce one FAD to FADH2
3. Phosphorylate one ADP (or GDP) to form ATP (or GTP)
and also 2 acetyl Co A = 2 cycles per glucose

Citric Acid Cycle

The citric acid cycle can be turned off at multiple points which is?

feedback inhibition

In the citric acid cycle the reaction rates are low when ATP or NADH are _________

abundant

Most of _________ __________ ________ is contained in the electrons transferred to NADH and FADH2

glucose's original energy

The electrons (and protons) are ultimately transferred to oxygen to form _______

water

The molecules that oxidize NADH and FADH2 are called the ______________ ___________ _________

electron transport chain (ETC)

What does the terminal electron acceptor form?

water

The ETC has 4 protein complexes

Complex I, Complex II, Complex III, Complex IV

___ is used to pump protons across the mitochondrial inner membrane into the inter membrane space and forms a strong electrochemical gradient

ETC

____ __________ is the enzyme that synthesizes ATP

ATP synthase