Chapter 9Cell Respiration

How much energy is in food?

One gram of _______ “burned” (oxidized) in presence of _______ = 3811 calories of heat energy

A _______ is the amount of _______ needed to raise the temperature of one gram of water one degree Celsius.

Kilocalorie on food labels (1 Calorie = 1000 calories) When cells “burn” glucose, they release

the _______ contained within its _______ bonds.

Oxygen or not? Anaerobic: “not in air”

Does not require _______• Glycolysis and fermentation

Aerobic pathways in cell respiration need _______ to release _______ from food.• Krebs cycle and ETC

Overview of Cell Respiration

Cellular respiration is the process that releases _______ by breaking down _______ in the presence of _______.

6O2 + C6H12O6 6CO2 + 6H2O + Energy

oxygen + glucose carbon dioxide + water + energy

Respiration Overview (3:50)

Study diagram on page 222.

The MIGHTY Mitochondrion

Glycolysis Process in which one molecule of _______ is broken

in half, producing two molecules of ________ _______ (pyruvate)

Energy input of ___ _____; ___ _____ produced; net gain of ___ _____.

2NAD+

4 ADP 4 ATP2 ADP2 ATP

22 Pyruvicacid

Two high-energy _______ and ____ picked up by NAD+ to make _______Energy in NADH carried to _____

No _______ needed and high _______ are the advantages.It’s a form of _____ production in O2-deprived cells

(muscle) and red blood cells (no mitochondria)

Glycolysis

2NAD+

4 ADP 4 ATP2 ADP2 ATP

2 2 PyruvicacidOverview of Glycolysis (3:00)

Fermentation

If there is no _______ present, cell will go through _____________

Cells convert _______ to NAD+ by passing high energy _______ back to _________, allowing glycolysis to continue producing a steady supply of _____.

__________ discovered it’s carried out by microbes

Alcoholic Fermentation Forms _____________ and _____ as wastes. Occurs mainly in _______ and a few other

microorganisms Causes bread dough to _______

• When yeast in dough run out of _______, they begin to ferment, giving off bubbles of ______.

• Small amount of alcohol evaporates. Process explained in 1897 by German

chemist Eduard Buchner – The birth of biochemistry!!!

C6H12O6 + zymase 2C2H5OH + 2CO2

Lactic Acid Fermentation Regenerates NAD+ so _______ can continue. Produced during vigorous exercise in _______

• Rapid production of ATP Lactic acid (lactate) is a _______ product

• Buildup of lactic acid in _____________ causes a painful, burning sensation, but only temporarily

• Broken down into ____ and _____ by liver Moves the metabolic burden from

___________ to ___________

Lactic Acid Fermentation

Metabolism of Lactic Acid – The Cori Cycle

• Cheese, yogurt, sour cream, pickles, and sauerkraut are all produced using lactic acid fermentation.

Lactic Acid Fermentation

Review The first step of cellular respiration

is…

Where does glycolysis occur?

What occurs if there no oxygen present after glycolysis?

Review What are the two types of

fermentation?

This type of fermentation occurs in muscle cells: ________________

Two types of phosphorylation in mitochondrion?

Glycolysis (review) Process in which one molecule of glucose is broken

in half, producing two molecules of pyruvic acid (pyruvate)

Energy input of 2 ATP

2NAD+

4 ADP 4 ATP2 ADP2 ATP

22 Pyruvicacid

Krebs Cycle During the Krebs

cycle, _________ is broken down into CO2 in a series of ________-extracting reactions.

Occurs in the _______ of mitochondrion.

First described by ______ _________ (1937)

aka: The Citric Acid Cycle

Krebs Cycle

Begins when __________ enters. One carbon from pyruvate becomes a part of _____ and is released from the cell.

At the same time, 2 _______ are combined with 1 H+ ion changing NAD+ into _____.

Next, _________ A joins the remaining 2 carbon molecules from pyruvate to form ________-CoA.

Acetyl-CoA adds its two- carbon acetyl group to a 4-carbon compound (oxaloacetate) producing ________ acid (citrate).

Krebs Cycle

_______ is broken down into a 5-carbon compound (alpha-ketoglutarate) and more _____ is released.

Again, 2 electrons and 1 H+ ion convert NAD+

to NADH. Then, another carbon

atom leaves in ____ as a waste product, leaving the 4-carbon compound _______ acid (malate).

Krebs Cycle Following that, NAD+

picks up 2 __________ and an ____ ion and becomes __________.

Also, ADP is converted into _____.

Next, ______ picks up 2 __________ and 2 _____ ions and becomes __________

Finally, another ______ picks up 2 __________ and an _____ ion and oxaloacetate moves on to start the cycle again.

Krebs Overview (1:55)

Where do the products of the Krebs Cycle go?

CO2 released into the _______ ATP used for cell activities NADH and FADH2 used to generate large

amounts of ATP in the ______.

Review Where does the Krebs cycle take

place?

Number of ATPs generated by Krebs for each molecule of glucose?

Two electron carriers generated by Krebs?

Waste product of Krebs?

Electron Transport Chain The ETC uses high-energy _______ from the _______

_______ to convert 32 ADPs to 32 ATPs. Series of carrier proteins located in inner ____________ of

______________.

ADP

High-energy _______ from NADH and FADH2 are passed from one carrier to the next.

At the end, an enzyme combines these electrons with H+ ions and oxygen to form _______.

________ serves as the final electron acceptor of the ETC.

ADP

Electron Transport Chain Each time 2 ________ travel down the ETC, their energy is

used to pump _____ ions across the membrane from the matrix to the intermembrane space of the ____________.

_____ ions build up in the intermembrane space, making it __________ charged and the outside __________ charged.

ADP

Electron Transport Chain This imbalance of _______ between the matrix and the

intermembrane space causes H+ ions to move through _____ ___________.

ATP synthase turns when this happens, converting _____ to _____

Average of 3 ATPs for every pair of _________

ADP

ETC Review (2:02)

Review Number of ATPs produced in ETC?

Waste product of ETC?

Purpose of energetic electrons?

Location of ETC in eukaryotes? Prokaryotes?

What enables ATP synthase to produce ATP?

So What’s the Point?? The overall goals of the four

pathways are:a. Glycolysis: to convert ________into ______ for fermentation or _______b. Fermentation: to produce ______

to keep _______ goingc. Krebs: to produce _______ and

_______ for the _____ d. ETC: to produce large amounts of _____ for the cell

How much energy does a single molecule of glucose provide?

Glycolysis = 2 ATP Krebs Cycle = 2 ATP ETC = 32 ATP

TOTAL = 36 ATP 18 times more ATP

produced with _______ Respiration extracts about

38 percent of total _______ of _______.

Remaining 62 percent released as ______

What happens when you need a burst of energy?

Your body contains enough _____ for only a few seconds of intense activity.

When you participate in vigorous ________, after a few seconds your body will begin to produce _____ by _______ _______ fermentation.

This type of ATP production will last about 90 _______.

What happens if you need energy for longer than 90 seconds?

________ respiration is the only way to generate a continuing supply of ______.

Releases ________ slower than fermentation.• Which means athletes need to train and pace

themselves. Body stores energy in muscle and other tissues

in the form of the carb ___________, which can supply energy for 15-20 mins.

After that, body breaks down stored molecules, like ________ &_______ for energy.

• This is why running, swimming, etc. are so good for weight control.

Comparing Photosynthesis and Respiration

_______ flow takes place in ________ directions• Photosynthesis

________energy; respiration ___________ energy

Cell respiration occurs in all eukaryotes and nearly all prokaryotes.

Photosynthesis occurs only in plants, algae, and some bacteria.

What happens to O2 and CO2 in plant cell?