BIOLOGY: UNIT 2 LECTURE EXAM

Where does cellular respiration mainly occur? Which types occur there?

mitochondria; Oxidation of Pyruvate and KREB cycle

what is the general reaction (formula) for cellular respiration?

C6H12O6 ——> 6CO2 +6H2O + ATP (opposite of photosynthesis)

What is the only reaction of cellular respiration outside of the mitochondria?

Glycolysis

What are the reactions of cellular respiration?

Glycolysis, The Oxidarion of Pyruvate (The Prepatory Reaction), The Citric Acid Cycle, harvesting energy by extracting electrons, and Oxidative Phosphorylation

What is the main goal of cellular respiration?

first make NADH and then use that to make ATP

Where does glycolysis occur?

cytoplasm

What is the net result of Glycolysis?

Input: 1 Glucose
Net Output: 2 PYRUVATE, 2 ATP, and 2 NADH

See an output of PYRUVATE and think ______.

Glycolysis

What happens during glycolysis?

break glucose in half to give 2 pyruvate molecules

What are the following products of glycolysis?

2 Pyruvate, 2 ATP, 2 NADH

The NADH produced in glycolysis must be brought into where in order for its energy to be used to make ATP?

mitochondria

How much does the transport of NADH into the matrix cost? (Active Transport)

1 ATP per NADH

When does the oxidation of pyruvate (preparatory reaction) occur?

after pyruvate enters the matrix

How many ATP are 2 NADH worth?

6 ATP

What is the junction point for fat, carbohydrate, and protein catabolism?

Acetyl CoA

What happens when fats and proteins are used for energy?

they are converted to pyruvate or acetyl CoA and fed into the citric acid cycle (this is why pyruvate is said to be standing at a biological crossroad).

What is the Net result of The oxidation of Pyruvate?

Input: 2 Pyruvate
Output: 2 ACETYL CoA, 2 NADH, and 2 CO2

See an output of ACETYL CoA and think ______.

oxidation of pyruvate

Where does the citric acid cycle occur?

in the matrix

What is another name for the citric acid cycle?

KREB cycle

What is the net result of the KREB cycle?

Input: 2 Acetyl CoA
Output: 6 NADH, 2 FADH2, 2 ATp and 4 CO2

See an output of FADH2 and think ______.

citric acid cycle (kreb cycle)

How many ATP per FADH?

2

What is cellulose?

glucose in a chain

What has energy that will be given to ATP when they pass electrons to the electron transport system?

NADH and FADH2

What are called oxidation?

electron transfer reactions

What is another word for Oxidative Phosphorylation?

The Electron Transport Chain

Where does oxidative phosphorylation occur?

along the inner membrane

What are electron transport chains?

linear arrangements of electron carriers

what is the final terminal electron acceptor?

oxygen

What is the most important thing to remember of Oxidative Phosphorylation?

the energy “lost” as electrons flow down the chain is used to make ATP

What is made using energy liberated from electron transfer during the chemiosmotic synthesis of ATP?

an H+ gradient

True or false:
ADP is phosphorylated (meaning a phosphate group is added to a molecule) when H+ flows through the ATP synthase down its concentration gradient.

true

which is spontaneous:
diffusion (down concentration) or active transport (up concentration)?

diffusion

What happens when molecules move from one to another?

it loses energy

How many ATP does 1 NADH make?

3 ATP

How many ATP does 1 FADH2 make?

2 ATP

How many total yield of atp do you get from glycolysis?

6

How many total yield of atp do you get from the oxidation of pyruvate?

6

How many total yield of atp do you get from the krebs cycle?

24

what is the total yield of atp from 1 glucose after cellular respiration?

36 ATP

What is fermentation?

ATP generation without oxygen and it is a less efficient way to make ATP

How many ATP does fermentation make?

2 ATP

What happens during alcohol fermentation?

turns pyruvate into alcohol

what happens during lactic acid fermentation?

turns pyruvate into lactic acid

what are the two types of fermentation?

lactic acid fermentation and alcohol fermentation

Both types of fermentation give how many ATP per glucose?

2 ATP

How many ATP per glucose from fermentation vs cellular respiration?

cellular respiration= 36 ATP

fermentation= 2 ATP


IN OTHER WORDS, THE TOTAL ATP YIELD OF CELL RESP. IS 36

What is the ultimate source of energy for almost all life forms?

the sun

What is kinetic energy?

The energy of motion

What is potential energy?

Stored energy

What is transport work?

Pumpping of substacnces across membranes against the direction of diffusion (active transport)

What is chemical work?

Using energy to “drive”chemical reactions that don’t occur spontaneously (by themselves)

What is the first law of thermodynamics?

Energy can be transformed (into different types of energy) and transferred, but not created nor destroyed

What is the second law for thermodynamics?

When energy is converted from one form to another, some of the energy becomes unavailable to do work (bc its lost); in other words- Every energy transformation or transfer increases the entropy of the universe.

What does entropy measure?

randomness (disorder)

less stable= _____ entropy

more

life orders itself- this is a move away from ______________

randomness

What is free energy?

The portion of a systems energy that can perform useful work (useful energy)

What does the way free energy changes during a reaction tell us?

if a process is spontaneous or not

what is a spontaneous process?

a process that occurs without any outside help

in spontaneous processes, what is released from a system?

free energy

what is it called if a reaction must be given free energy to go forward?

nonspontaneous

What is entropy?

a form of energy that is not useful for doing work (if you see entropy, think second law)

What does exergonic mean?

from outside

What is an endergonic reaction?

energy is absorbed (inside)

What happens in an exergonic reaction?

Energy is released as the reaction proceeds

Which reaction is SPONTANEOUS: exergonic or endergonic

Exergonic

Which reaction is NONSPONTANEOUS: exergonic or endergonic

Endergonic (so you must add energy to make it go).

What is energy coupling?

where the energy released by an exergonic reaction is used to drive an endergonic reaction forward- much of a cell’s work involved driving nonspontaneous reactions forward using energy released by spontaneous reactions.

What does converting ADP to ATP require?

An input of energy

What does converting ATP to ADP require?

An output of energy from removing a phosphate from ATP

What are enzymes?

Molecules that make reactions go faster; protein catalysts

What is kinetics?

the study of the rate of reactions

Why do spontaneous reactions go forward incredibly slowly in biology?

They are blocked by an energy barrier.

What are catalysts?

atoms or molecules that increase the rate of a reavtion eithout being used up in the reaction.

What is the activation energy?

The energy barrier that blocks spontaneous reactions.

What lowers the activation energy?

enzymes

Enzymes are _______

specific. Each type only reacts with certain molecules

What are substrates?

the chemical enzymes that act on reactants

What is the recognition of particular substrate by a particular enzyme based on?

the 3D shapes of the enzyme and its substrate

Where do substrates interact with enzymes?

the active site

What is the active site?

the area on an enzyme where the substrate is recognized, bound, and caused to react.

What kind of reactions can enzymes ONLY speed up?

spontaneous; enzymes CANNOT make non-spontaneous reactions go.

How can nonspontaneous reactions be made to go?

if they are coupled to a spontaneous reaction (energy coupling)

What does optimum temperature mean?

ideal or best temperature

What do enzyme inhibitors do?

Slow down enzymes

What are irreversable inhibitors?

molecules that bind permanently to the active site and render it useless, “killing” the enzyme

What are reversable inhibitors?

molecules that interfere with enzyme activity by temporarily binding to the enzyme. (there are 2 kinds)

What is the difference between reversable inhibitors and irreversable inhibitors?

irreversable bind permanently while reversable bind temporarily

What are the 2 types of reversable inhibitors?

competitive inhibitors and noncompetitive inhibitors.

What are competitive inhibitors?

compete w substrate for the active site

What are noncompetitive inhibitors?

bind at the enzyme anywhere other than the active site.

What is the overall reaction for photosynthesis (formula)?

6CO2 + 6H2O + sunlight —> C6H12O6 + 6O2 (glucose + 6 oxygen)

Where does photosynthesis occur?

In chloroplasts

Why are chloroplasts all green?

Because of the presence of chlorophyll

What does chlorophyll do?

Absorbs the light energy used to make glucose from CO2 and H2O

What are the openings that CO2 and O2 enter and exit the area around chloroplasts called?

Stomata

What are the 2 basic organ systems the body of a plant is separated into?

The root system, and the shoot system

What are the 3 principal organs plants have?

leaves, stems, roots