AP BIO unit 3

Identify the two wavelengths are predominantly absorbed by chlorophyll.

red (650 nm) and blue (450-495 nm)

where does the mass of a tree come from? what is the source of wood? sugars?

The mass of a tree is primarily carbon. The carbon comes from carbon dioxide used during photosynthesis. During photosynthesis, plants convert the sun's energy into chemical energy which is captured within the bonds of carbon molecules built from atmospheric carbon dioxide and water

Define carbon fixation. Identify the reaction of photosynthesis that fixes carbon.

carbon fixation is the process wherein photosynthetic organisms turn inorganic carbon into organic compounds. Light-independent reactions fix carbon. first step in calvin cycle

Identify 3 reasons why glycolysis is considered to be the first metabolic process in a common, evolutionary ancestor. Justify your answers.

glycolysis is considered to be the first metabolic process in a common, evolutionary ancestor because: 1. it does not require organelles or specialized features. it is present in most organisms. because it doesn't require organelles or specialized features, this means it was able to fuel organisms before evolution occurred, producing organelles and specialized features that weren't present in the beginning of time. 2. It doesn't require oxygen. Oxygen became prevalent in earth's atmosphere 2.5 to 3 billion years ago. before then, oxygen isn't available to aid in fueling organisms. Because glycolysis doesn't require oxygen, this was able to be used since the beginning of time. 3. glycolysis is prevalent in all living organisms, indicating that it must be an ancient process because it had to be around since the beginning of time for all organisms to be able to use it.

why does the wrong pH decrease enzymatic activity?

if an enzyme isn't at its ideal pH, it will decrease activity as it denatures.

why does photosynthesis happen in a series of coordinated steps?

light dependent reactions of photosynthesis occur in a series of coordinated reaction pathways that capture free energy present in light to yield ATP and NADPH, which power the production of organic molecules.

why do high temperatures increase enzymatic activity?

molecules move faster in higher temperatures. increasing enzymatic activity

why do low temperatures decrease enzymatic activity?

molecules move slower in lower temperatures, which would decrease enzymatic activity

is photosynthesis spontaneous or nonspontaneous?

nonspontaneous because it is endergonic.

reactant reduced during cellular respiration

oxygen

why is photosynthesis important for life on earth?

photosynthesis allows plants to grow, and self-nurture. By photosynthesis keeping the plants alive, through the process of cellular respiration, plants expel oxygen, which allows life on earth to thrive.

where does CO2 created in cellular respiration come from?

processes of decay of organic materials

does the entire reaction of photosynthesis require light?

yes, because that is where the energy is sourced from to carry out functions.

light independent reactions reactants in: products out: what is oxidized: what is reduced: location: when does it happen:

- ATP, CO2, NADPH - ADP + Pi - H2O - O2 - stroma - after light reactions

oxidative phosphorylation summary reactants in: products out: what is oxidized: what is reduced: location: when does it happen:

- NADH, FADH2, O2 - NAD+, H2O, ATP, FAD+ - FADH2, NADH - NADH - mitochondrial inner membrane - when O2 is available

pyruvate oxidation summary reactants in: products out: what is oxidized: what is reduced: location: when does it happen:

- coenzyme a, pyruvate, NAD+ - acetyl-CoA, NADH, CO2 - CO2 - NAD+ - cytoplasm - before kreb's

functions of calvin cycle

- make organic products that plants need using products from light reactions of photosynthesis

fermentation summary: reactants in: products out: what is oxidized: what is reduced: location: when does it happen:

- pyruvate - lactic acid, ethanol + CO2, H2O - NADH - pyruvate - cytoplasm - when O2 is not available

function of photosystem II

- water splitting - oxygen evolution - plastoquinone reduction

light dependent reactions reactants in: products out: what is oxidized: what is reduced: location: when does it happen:

-ADP + Pi, NADP+, H2O - ATP, NADPH - H2O - CO2 - thylakoid - when light is available

function of photosystem I

-NADPH synthesis -Absorb light that excites electrons to the P700 chlorophyll -Transfer electrons to the primary electron acceptor -Transfer electron to the electron carrier Fd

krebs cycle summary reactants in: products out: what is oxidized: what is reduced: location: when does it happen:

-acetyl CoA - NADH, FADH2, CO2, ATP - acetyl CoA - FADH2, NADH - mitochondrial matrix - after glycolysis

Glycolysis summary: reactants in: products out: what is oxidized: what is reduced: location: when does it happen:

-glucose - ATP, NADH - glucose - NAD+ - cytoplasm - first step in cellular respiration

Membranes must be fluid to function properly. How does the operation of the electron transport chain support that assertion?

A function of the ETC chain is ubiquinone, (vitamin). this needs to be diffused through the membrane and would only be able to do this in liquid conditions, because in solid conditions, it is challenging to travel through the membrane.

Explain how chemiosmosis, ATP synthase, ATP production and the proton gradient are related.

ATP synthase is the enzyme that produces ATP through chemiosmosis. the energy created allows protons to travel through the proton gradient through chemiosmosis

What makes C4 photosynthesis more efficient than C3 photosynthesis in tropical climates?

C4 photosynthesis is more efficient than C3 photosynthesis in tropical climates because they have a higher rate of photosynthesis and a reduced rate of photorespiration

How is CAM photosynthesis advantageous in desert climates?

CAM photosynthesis has the advantage in desert climates because it has an adaptation in arid conditions (desert) that allows plants to photosynthesize during the day, and only exchange gases during the nigh

In the absence of O2, as in question 27, what do you think would happen if you decrease the pH of the intermembrane space of the mitochondrion? Explain your answer.

If the pH was decreased in the intermembrane space of the mitochondrion, then there would be an increase in ATP production. This would be because low pH increases the concentration of the base, leading to higher ATP production

what role did photosynthesis play on the evolution of earth? How did it change the atmosphere? How did this affect life on earth?

Photosynthesis introduced oxygen to earth, changing the atmosphere from mainly being CO2 to O2, and affected life on earth by creating organisms that were aerobic.

Why is it so important that cells undergo respiration and not combustion?

because cellular respiration is more efficient than combustion. combustion uses energy for movement whereas cellular respiration uses energy for cellular work

Why could we call photorespiration a "mistake" in the functioning of the cell?

because it is a process in plant metabolism where the enzyme RuBisCO oxygenates RuBP, wasting some of the energy produced by photosynthesis.

what energy conversion is taking place during photosynthesis?

chemical

Is photosynthesis endergonic or exergonic?

endergonic; the energy boost is provided by light

reactant oxidized during cellular respiration

glucose

why is it so important that humans breathe in oxygen?

to obtain energy and carryout functions

Why do plants have to perform both photosynthesis and cell respiration? Why isn't photosynthesis 'enough'?

Photosynthesis is the creation of nutrients in a plant. Photosynthesis is responsible for creating glucose, which is energy for the plant, allowing it to grow. Cellular respiration, however, is the release of energy out of the plant, and use glucose produced from photosynthesis to produce ATP to carry out the functions of a plant. Without cellular respiration, photosynthesis would be useless.

In biology 1, we often teach that photosynthesis is the opposite of cell respiration. Explain this in terms of the overall reactants, products, and the steps involved

Photosynthesis: 6CO2+6H2O → C6 H12 O6 +6O2 Cellular respiration: C6 H12 O6 + 6O2→ 6CO2+6H2O cellular respiration is photosynthesis backwards. its reactants are photosynthesis' products.

Compare substrate-level phosphorylation and oxidative phosphorylation. Identify the stage(s) of cell respiration where each occurs.

substrate-level phosphorylation: the enzyme-catalyzed formation of ATP by direct transfer of a phosphate group to ADP from an intermediate substrate in catabolism. Occurs in glycolysis and krebs Oxidative phosphorylation: the production of ATP using energy derived from the redox reactions of an ETC chain; third major stage of cellular respiration. Occurs in ETC

what affect would the absence of O2 have on chemiosmosis?

the absence of O2 on chemiosmosis would result in the chain not working because there would be no O2 to accept electrons and ATP would no longer be produced.

Explain the induced fit model of enzyme functioning.

the induced fit model states a substrate binds to an active site and both change shape slightly, creating an ideal fit for catalysis.

Before falling, many leaves change colors as the chlorophyll is broken down, revealing what we call 'accessory pigments.' These pigments are proteins, meaning that the colors & amounts are genetically determined. What do you think might be the function of these pigments?

to help plants absorb additional light

O2 released from plants comes from what

water splitting

where does the H2O created in cellular respiration come from?

when hydrogen and oxygen react to form H2O