Download Biology I – Cellular Respiration Name: :________Hour:______ OK

Biology I – Cellular Respiration
Name:________________________________________________Date:________Hour:_______
OK OK OK.. I’m sure you all thought that I wouldn’t possibly ask you to know more for this
chapter… SORRY!
Now, we need a place to disassemble the __________________ molecule and release all that
stored up energy we put in it during _____________________.
 Where does this occur (which organelle)? _____________________
 Where do we find this organelle? ________________________
 What types of cells would we find lots of these organelles in? ___________________
Animals, including humans get most of their ___________ from the food they _____________.
The energy in _____________ is stored in proteins, carbohydrates, and fats.
Our cells transfer _______________in organic compounds, especially glucose, to ATP through
_____________________________.
So, we ate a meal of spaghetti. Spaghetti contains lots of ______________________. As we
digest spaghetti, these carbohydrates get ______________________.
What types of organisms undergo cellular respiration? ________________________________
Step 1 of Cellular Respiration is ________________ – Glycolysis means to “split glycogen”
The primary fuel for cellular respiration is ___________________
 Glucose is formed when ___________________________, like starch and glucose, are
broken down.
o If not enough carbohydrates are consumed, organisms can break down
______________ to make ATP
 ______ gram of fat releases more energy than _________ grams of
carbohydrates do
o Proteins and nucleic acids can be used too… but the cell uses them to
___________ other cell parts
OK.. So.. Now for the steps of glycolysis – Having fun yet??
Glycolysis occurs in the ________________
Step 1 – Breaking Down Glucose
 ________ ATP molecules help break down glucose into two smaller units
 A _________________ from ____________ is added to the 6-carbon compound
o Now, the molecule is reactive
 An enzyme will now break it into two 3-carbon sugars, each with a
phosphate group
Step 2 – NADH Production
 Each 3-carbon compound reacts with another ________________ group (not from ATP)
 As they (3-carbon compounds) react further, _________________ atoms including their
electrons are _________________to two molecules of NAD+
o This produces two molecules of the electron carrier _______________,
 NADH is used in other cell processes
Step 3 – Pyruvate Production
 3-carbon ________________ is converted into a 3-carbon molecule of ______________
o Process produces __________ ATP molecules
In glycolysis, there is a net gain of ______ ATP molecules
__________________is the starting material in glycolysis. There are three products. What are
the three products? Use figure 11 on page 209 to assist you. ___________________________
The only source of energy for some ______________________ is glycolysis
Glycolysis is an ___________________ process
 Anaerobic means?
Some organisms use oxygen to release even more energy from glucose. These processes are
aerobic.
 Aerobic means?
How are the products of photosynthesis and cellular respiration related?
Aerobic Respiration requires ________________
The Krebs cycle requires ____________________
The Krebs cycle converts _________________ from glycolysis into _____________&________
 Pyruvate releases a _____________________ molecule to form a 2-carbon compound
o An enzyme attaches this 2-carbon compound to a 4-carbon compound
 forms a 6-carbon compound
 The 6-carbon compound releases one carbon dioxide molecule, and then another
o __________________ is released each time
 This energy forms an electron carrier, ______________
 The remaining 4-carbon compound is converted back to the 4-carbon compound that
began the cycle
o Conversion takes place in a series of steps that produce ATP, then FADH2, and
another NADH
 The 4-carbon compound combines with a new 2-carbon unit from pyruvate to continue
the cycle
Products of the Krebs cycle
 Each time the carbon-carbon bonds are rearranged or broken, _____________ is
released
o Total yield from one time through Krebs Cycle is one __________, three _______,
and one ___________
o Electron carriers _____________ energy through the electron transport chain,
which powers ATP synthase
Electron Transport Chain
The 2nd stage of the aerobic respiration is the _____________________________
This takes place in the inner membranes of the ___________________________
1. The _____________ carried by NADH and FADH2 pass through electron transport chain
 Energy is transferred into each molecule through which the electrons pass
 Some of the molecules are hydrogen ion pumps
2. Energy from the electrons is used to _____________ transport hydrogen ions, out of the
inner mitochondrial compartment
 As H+ accumulate in the outer compartment, a _________________________
across the inner membrane is created
3. Hydrogen ions __________ through _________________ on the inner membrane of the
mitochondria
 Movement provides energy
 Energy is used to produce several ATP molecules from ADP
4. An oxygen atom ___________________ with these electrons and two H+ ions to form
two water molecules
 If oxygen is not present, the ETC __________________.
 Electron carriers cannot be ___________________
 So Krebs cycle also stops
 Without oxygen, a cell can produce ATP only by _____________________
So let’s review… All of the above for what yield?? 1 ATP, 3 NADH, and 1 FADH2 . That’s a crazy
amount of work for what seems like very little energy.. Especially crazy when you know learn
the next statement…
Just so you know……… The human body uses about 1 million molecules of ATP per cell per
second. There are more than 100 trillion cells in the human body. That’s about
100,000,000,000,000,000,000 ATP molecules used in your body each second..
OK.. Now we move on to fermentation
Fermentation uses the pyruvate that was formed in glycolysis to further break down
carbohydrates in the absence of oxygen
Think back.. What does the electron transport chain require? ____________________
The two ATP molecules and one molecule of the electron carrier NADH needs to transfer
electrons to convert pyruvate into ATP. In the absence of oxygen, there must be another
way… This way is fermentation
There are two types of fermentation: lactic acid fermentation and alcoholic fermentation
Lactic Acid Fermentation
 Pyruvate is converted to ________________
 Occurs in ______________cells during vigorous exercise
o During vigorous exercise, cells go with little or no ________________
o ___________________ becomes only source of ATP as long as glucose lasts
Alcoholic Fermentation
 An ________________ removes carbon dioxide from the 3-carbon pyruvate to form a 2carbon molecule
 A second enzyme adds electrons and hydrogen from NADH to the molecule to form
___________________
In both lactic acid fermentation and alcoholic fermentation, ___________ is recycled to be
used in glycolysis again.
Using the above image, answer the following questions.
What is necessary for cellular respiration to occur? _________________
What happens next? __________________. This process nets_________ ATP
What is the product of glycolysis? ____________________
In the presence of oxygen, what happens next? ______________________then, ___________
In the absence of oxygen, what happens after the production of pyruvate? ________________
What are the two types of fermentation and what are their products?
If after the Krebs cycle is complete, oxygen becomes unavailable, what happens? (page 211)
If oxygen is still available after the Krebs cycle is complete, how many total ATP can be
produced by the Krebs cycle and electron transport chain collectively? _____________. Now
include glycolysis as well.. __________
Efficiency of Cellular Respiration
The total amount of ATP produced in cellular respiration depends on the presence or absence
of _________________
In the first stage of cellular respiration, ________________is broken down to
_______________ during glycolysis
 Glycolysis is an ________________ process
o Results in net gain of __________ ATP
In the second stage of cellular respiration, pyruvate either passes through the
___________________ or undergoes _______________________
 When oxygen is not present, _____________________ occurs
 The NAD+ that is recycled during fermentation allows glycolysis to continue producing
ATP
Cells release energy most efficiently when _______________ is present
For each molecule of glucose, _________ ATP molecules are produced during the __________.
 The Krebs cycle feeds NADH and FADH2 to the ________________________________
o Electron transport chain can produce up to _______ ATP molecules