Chapter 6 - Campbell Essential Biology with Physiology 4th Edition (Simon, Dickey, Reece)

What is Cellular Respiration?

the breakdown of glucose that produces energy.

Where does cellular respiration take place?

mitochondria

What are the two types of cellular respiration?

aerobic and anaerobic

What is Aerobic Respiration?

breakdown of glucose in the presense of oxygen

What is Anaerobic Respiration

breakdown of glucose in the absense of oxygen.

What does both Aerobic and Anaerobic Respiration have in common?

they both breakdown glucose into ATP energy

What happens when you excercise?

1)Starts with Aerobic Respiration.

2)Reach aerobic capacity (which is the maxium rate at which oxygen can be taken in and used by your cells.)

3)Switch to anaerobic respiration (you exceed your aerobic capacity, incurring an O2 deficit - lactic acid builds up at which point you feel the burn)

4)Collapse (too much lactic acid builds up and not enough oxygen)

At both the organismal and cellular levels, respiration involves taking in the gas ______ and expelling the gas _______

O_2 and CO_2

How do you know when you have switched from aerobic to anaerobic respiration?

when you begin sweating, which is the body's homeostatic response to cool the body temperature.

What is the relationship between photsynthesis and cellular respiration?

Autotrophs conduct photosynthesis and cellular respiration (uses CO2 and H2O produced by respiration). Heterotrophs by contrast conduct cellular respiration (uses glucose and O2 produced by photosynthesis).

What is the relationship between breathing and cellular respiration?

breathing is the intake of oxygen and the removal of CO2 from the lungs. cellular respiration then breaks down glucose (by cells) in the presence of oxygen to produce energy (ATP).

What is the link between photosynthesis and cellular respiration?

Photosynthesis happens in the presence of sunlight. If there is no photosynthesis, cellular respiration does not take place.

What is misleading about the following statement? "Plants have cholorplasts that perform photosynthesis, whereas animals have mitochondria that perform cellular respiration."

It implies that cellular respiration does not also occur in plants. It does.

What is the cellular respiration equation?

C_6H_12O_6 +6O_2 ---------> 6CO_2 + H_2O + ATP

Two points to remember with cellular respiration

1) 38 ATP molecules are produced for every glucose molecule broken down

2) Hydrogen released from the glucose is picked up by the oxygen to form water.

Roadmap for Cellular Respiration

Step 1 - Glycolysis takes place in the cytoplasm of the cell causing glucose to break down to pyruvic acid.

Step 2 - Krebs' cycle takes place in the matrix (cristae) of the mitochondria where pyruvic acid is diffused into the matrix. Electrons released are picked up by coenzymes.

Step 3 - Electron Transport takes place on the outer compartment of the inner membrane of the mitochondria where coenzymes deliver electrons to the ETS

Step 4 - the ETS delivers the electrons to oxygen and ATP is formed.

What is the ETS?

Electron Transport System.

What are Redox reactions?

reactions in which one substance is oxidized and the other reduced.

What are the 4 different Redox Reactions?

1)Oxidation

2)Reduction

3)Phosphorylation

4)Dehydration

What happens with Oxidation?

the loss of electrons

What happens in Reduction?

gaining of electrons

What is Phosphorylation?

addition of phosphate, phosphate is added from ATP or from an inorganic free floating phosphates

What is dehydration?

removal of water

During a redox reaction, the addition of electrons is called ________, while the removal of electrons is called ________.

reduction, oxidation

What stages of cellular respiration take place in the mitochondria?

the citric acid cycle (Krebs' cycle) and electron transport

Remember OLRG

Oxidation is the loss of electrons, Reduction is the gain of electrons.

What is the Electron Transport Pathway?

A series of molecules on the inner membrane of the mitochondrion.

What happens in the Electron Transport Pathway?

1) Electrons move from protein to protein in the chain

2)Hydrogen ions are tossed out into the outer compartment

3)The Hydrogen ions then diffuse through ATP synthases into the inner compartment.

4) ATP synthases rotate activating active sites which helps ADP bind with Phosphate to produce ATP

What happens if oxygen is replaced by another gas in the environment (Test Question)?

ETS shuts down, no ATP is produced and cells stop working leading to death.

What happens during Strenuous activity?

The body incurs an oxygen debt, switches to anaerobic respiration, lactic acid accumulates, gluconeogensis converts lactic acid to pyruvate and back to gluccose in the liver (requires large amounts of oxygen and ATP).

What are Aerobes?

organisms that breakdown glucose in the presense of oxygen.

What are Anaerobes?

organisms that breakdown glucose in the absense of oxygen.

What are Obligate Anaerobes?

dies in the presense of oxygen.

What are Facultative Anaerobes?

conduct anaerobic respiration when oxygen is absent and aerobic respiration when oxygen is present.

What happens in Humans?

as a whole, humans are obligate aerobes, but our cells behave like facultative anaerobes.

Two molecules of what compound are produced by glycolysis? Does this molecule enter the citric acid cycle?

Pyruvic acid. No, it is first converted to acetic acid.

What is the potential energy source that drives ATP production by ATP synthase?

a concentration gradient of H+ across the inner membrane of a mitochondrion.

Which stage of cellular respiration produces the majority of ATP?

electron transport

How many molecules of ATP can be produced from one molecule of glucose during fermination?

2

Why is Fermintation an inefficient way of breaking down glucose to ATP?

Only 2 ATP total are produced versus the 38 ATP that are produced with Aerobic respiration. There is no O2 present to run the ETS.

What kind of acid builds up in human muscles during strenous activity?

lactic acid

What is a by-product of photosynthesis?

O2

In both plants and animals, where is the majority of ATP produced?

in the mitochondria.

Where are the enzymes located for glycolysis?

In the cytoplasm.

How many total NADH & FADH_2 are produced from Glycolysis through the Krebs' Cycle? How is the production broken down?

10 NADH + 2 FADH_2. Glycolysis produces 2 NADH, The Initial Steps produce another 2 NADH. The Krebs' Cycle produces 6 NADH and 2 FADH_2.

What are the two types of Anaerobes?

1)Obligate Anaerobes

2)Facultative Anaerobes

How does NAD+ become NADH + H+?

NAD+ is positively charged meaning that it has more protons than electrons. NAD+ becomes NADH + H+ when 2 H atoms give up electrons to NAD+. One Hydrogen attaches and the other Hydrogen that gave up its electron become a Hydrogen Ion or H+