Download AP Biology Unit 3 Packet- Respiration and

AP Biology Unit 3
AP Biology Unit 3 Packet
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Cellular Respiration—Chapter 7
Photosynthesis—Chapter 8
Topics:
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Cellular Respiration
Fermentation
Photosynthesis
Key Terms Chapter 7
a.
b.
c.
d.
e.
f.
Fermentation
Aerobic respiration
Redox reaction
Electron transport chain
Glycolysis
Krebs cycle
g.
h.
i.
j.
k.
Oxidative phosphorylation
Chemiosmosis
Matrix
Inner membrane
Outer membrane
h.
i.
j.
k.
l.
m.
n.
u.
v.
w.
x.
Thylakoids
Stomata
Guard cells
Light reactions
Dark reactions
Chlorophyll a
Chlorophyll b
CAM photosynthesis
Photophosphorylation
P680
P700
Key Terms Chapter 8
a.
b.
c.
d.
e.
f.
g.
o.
p.
q.
r.
s.
t.
Chloroplasts
Cuticle
Upper epidermis
Palisade parenchyma
Spongy parenchyma
Stroma
Grana
Carotenoids
Photosystem I
Photosystem II
NADPH
Carbon fixation (C3 pathway)
C4 oxaloacetate pathway
Recommended work for Chapters 7 & 8:
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Concept Checks
Test Your Understanding Level 1 & 2
AP Biology Unit 3
Cellular Respiration
In cellular respiration, which is performed by all organisms, ATP is produced through
the breakdown of nutrients. You’ll recall from unit 1 that many organic molecules
are important to cells because they are energy-rich.
Write out the balanced summary equation for cellular respiration.
Notice that sugar is taken, perhaps a molecule of glucose, and it’s combined with
oxygen to produce carbon dioxide, water, and energy in the form of ATP.
Define ATP:
Generally speaking, we can break cellular respiration down to two different
approaches: aerobic respiration or anaerobic respiration.
Define aerobic respiration:
Define anaerobic respiration:
Aerobic Respiration
Aerobic respiration consists of four stages: (1) glycolysis, (2) formation of acetyl
CoA, (3) the Krebs cycle, and (4) oxidative phosphorylation.
Stage 1: Glycolysis
The first stage begins with glycolysis, the splitting of glucose. Glucose is a six-carbon
molecule that is broken into two three-carbon molecules called pyruvic acid. This
breakdown of glucose also results in the net production of two molecules of ATP.
AP Biology Unit 3
Write out the series of reactions for glycolysis, glucose to pyruvic acid, include ATP,
ADP, NAD+, and NADH.
Fortunately, you don’t need to memorize these steps for the test. What you do need to
know is that glucose doesn’t automatically generate ATP. It has to be “activated”. Once
glucose is phosphorylated or “powered up”, it eventually splits into two pyruvic acids.
If you take a good look at the reaction above, you’ll see two ATP’s are needed to produce
four ATP’s. Two ATP’s yielded four ATP’s, for a net gain of two.
A second product in glycolysis is 2 NADH, which results from the transfer of H+ to the
hydrogen carrier NAD+. NADH will be used elsewhere in respiration to make additional
ATP. There are four important parts to remember regarding glycolysis.
Answer the following items:
1. Where in the cell does glycolysis occur?_________________________________
2. How many ATPs are produced?_____________Net ATPs produced?_________
3. Hwo many pyruvic acids are formed?___________________________________
4. How many NADH’s are produced?_____________________________________
AP Biology Unit 3
Once the cell has undergone glycolysis, it has two options: It can continue anaerobically,
or it can switch to true aerobic respiration. If oxygen is present, many cells switch
directly to aerobic respiration. If no oxygen is present, those same cells may carry out
anaerobic respiration. Still others have no choice, and carry out only anaerobic
respiration, with or without oxygen.
Important organelle: MITOCHONDRIA
Draw and label the mitochondria, include the matrix, the inner mitochondrial
membrane, the intermembrane space, the outer membrane, and the cristae.
Stage 2: Formation of Acetyl-CoA
When oxygen is present, pyruvic acid enter the mitochondria. Each pyruvic acid is
converted to acetyl coenzyme A and CO2 is released:
Write out the balanced equation for the above reaction.
Keep tract of the carbons. The molecules now have gone from a three-carbon molecule to
a two-carbon molecule. The extra carbons leave the cell in the form of CO2. Once again,
two molecules of NADH are also produced
AP Biology Unit 3
Stage 3: The Krebs Cycle
The next stage is the Krebs cycle, also known as the citric acid cycle. Each of the two
acetyl-CoA molecules will enter the Krebs cycle, one at a time, and all the carbons will
ultimately be converted to CO2.
How does the Krebs cycle occur?___________________________________________
Write out the Krebs cycle, starting with pyruvic acid reacting with oxaloacetate and
ending with oxaloacetate. Include NAD+, NADH, GDP, GTP, ADP, ATP, FAD, and
FADH2.
Track the carbons again. Each molecule of acetyl-CoA produced from the second stage of
aerobic respiration combines with oxaloacetate, a four-carbon molecule, to form a sixcarbon molecule, citric acid or citrate.
Since the cycle begins with a four-carbon molecule, oxaloacetate, it also has to end with
a four-carbon molecule to maintain the cycle. So how many carbons do we have to lose
to keep the cycle going? Two carbons, both of which will be released as CO2. Now the
cycle is ready for another turn with the second acetyl-CoA.
AP Biology Unit 3
With each turn of the cycle, three additional types of molecules are produced:
1. How many ATPs are produced?_______________________
2. How many NADHs are produced?_____________________
3. How many FADH2 are produced?_____________________
Stage 4: Oxidative Phosphorylation
It was said earlier that ATP is the energy currency of the cell. While this is true, ATP is
not the only molecule that stores energy. Sometimes energy is stored by electrons
carriers like NAD+ and FAD. Electrons are transferred form electron carriers to oxygen,
resulting in ATP synthesis. This process is called oxidative phosphorylation.
Electron Transport Chain
As electrons are removed form a molecule of glucose, they carry with them much of the
energy with them that was originally stored in their chemical bonds. These electrons, and
their accompanying energy, are then transferred to readied hydrogen carrier molecules. In
the case of cellular respiration, these charged carriers are NADH and FADH2.
How many “loaded” electrons carriers have been prodeceued?
1. How many NADHs from glycolysis?
______________
2. How many NADHs from the production of acetyl-CoA?
______________
3. How many NADH from the Krebs cycle?
_______________
4. How many FADH2 from the Krebs cycle?
_______________
Total = _________________
Draw and label the electron transport chain, start with FMN reacting with NADH, and
ended with the formation of water.
What is the significance of oxygen in this process?
AP Biology Unit 3
Chemiosmosis
At the same time that electrons are being passed down the electron transport chain,
another mechanism is at work. Remember those hydrogen ions (protons) that split off
from the original hydrogen atom? Some of the energy released from the electron
transport chain is used to pump hydrogen ions across the inner mitochondrial
membrane to the intermembrane space. The pumping of the hydrogen ions into the
intermembrane space creates a pH gradient, or proton gradient. The potential energy
established in this gradient is responsible for the production of ATP.
These hydrogen ions can diffuse across the inner membrane only by passing through
channels called ATP synthase. Meanwhile, ADP and Pi on the matrix side of the
channel. This process is called oxidative phosphorylation.
Draw and label a diagram of the mitochondria illustrating the above process.
Summary Chart
STAGES OF AEROBIC RESPIRATION
Step in Respiration
Takes Place in the …
Net Result
Glycolysis
Split to acetyl-CoA
Krebs Cycle
Oxidative
Phosphorylation
NET ATPs:
AP Biology Unit 3
Anaerobic Respiration
Some organisms can’t undergo aerobic respiration. They’re anaerobic. They can’t use
oxygen to make ATP. These organisms and other cells carry out a process called
fermentation. Under anaerobic conditions, pyruvic acid is converted to either lactic acid
or ethyl alcohol (ethanol) and carbon dioxide.
You should remember the two pathways anaerobic organisms undergo: glycolysis and
fermentation. Anaerobic fermentation is not very efficient. It only results in a net gain of
2 ATP for each molecule of glucose broken down.
Draw out the process of both types of fermentation (lactic acid fermentation and
alcoholic fermentation).
Photosynthesis
What are of organisms carry out photosynthesis?
Write out the summary equation for photosynthesis.
Draw and label the anatomy of a leaf, include palisade parenchyma, chloroplast,
spongy parenchyma, air space, guard cell, stomata, lower epidermis, vascular bundle
(vein), upper epidermis, and cuticle.
AP Biology Unit 3
Draw and label a diagram of a chloroplast, include stroma, grana, thylakoid. and outer
membrane.
There are two stages in photosynthesis: the light reactions (the light-dependent reaction)
and the dark reaction (the light-independent reaction).
Draw and label a diagram to summarize the light reactions (noncyclic
photophosphoryaltion), include photon, reaction center, antenna complex, antenna
molecules, photosystem I and II, P680, P700, ATP, electron transport chain, water,
NADP+, NADPH.
AP Biology Unit 3
Draw and label a diagram illustrating cyclic photophosphorylation.
Draw and label a diagram to summarize the dark reactions, the CALVIN CYCLE (C3
Pathway).
Describe C4 Photosynthesis.
Describe CAM Photosynthesis.
Describe photorespiration.
AP Biology Unit 3
Grid-In Questions (these require a numerical response)
1. The following chart shows the energy products produced in various stages of the
breakdown of glucose.
Process
Glycolysis
Pyruvate Oxidation
(per molecule of pyruvate)
Citric Acid (Krebs) Cycle
(per molecule of pyruvate)
ATP Produced
2
NADH/FADH2 Produced
2 NADH
1 NADH
1
3 NADH
1 FADH2
Each molecule of NADH results in approximately 2.5 molecules of ATP, whereas each
molecule of FADH2 results in approximately 1.5 molecules of ATP when these
molecules are fed into the electron transport chain.
a. What is the difference in the total number of ATP molecules produced between three
molecules of glucose that undergo fermentation compared to three molecules of glucose
that undergo aerobic respiration?
Answer:_____
b. Glutamine is formed from glutamic acid by adding an ammonium molecule. The
overall reaction is endergonic, requiring 3.4 kcal/mole. The energy for the reaction
comes from the exergonic splitting of a phosphate from ATP to form ADP, which
releases 7.3 kcal/mole. What is the free energy change for this coupled reaction?
Answer:_____
2. An enzyme in the liver removes a phosphate group from glucose so the glucose
molecule can enter the bloodstream, providing energy for cellular respiration to the cells
of the body. The rate of enzyme activity can be monitored by measuring the phosphate
concentration over time. In this experiment, liver cells were placed on a phosphate
solution, and every 5 minutes cells were removed and the intracellular concentration of
phosphate was measured. What is the rate of phosphate formation from 15 to 20 minutes?
Time (min)
0
5
10
15
20
Phosphate Concentration in Liver Cells
(umol/ml)
0
10
90
180
270
Answer:____
AP Biology Unit 3
Essay #1
DESCRIBE THE BIOCHEMICAL PATHWAYS OF THE LIGHT AND DARK
REACTIONS IN C3 PHOTOSYNTHESIS. BEGIN WITH A MOLECULE OF H2O
AND CO2 AND END WITH A MOLECULE OF GLUCOSE.
AP Biology Unit 3
Essay #2
DISCUSS HOW C4 AND CAM PHOTOSYNTHESIS IMPROVE UPON C3
PHOTOSYNTHESIS. INCLUDE BOTH ADVANTAGES AND DISADVANTAGES
OF THE PROCESSES. DESCRIBE APPROPRIATE LEAF ANATOMY TO
COMPLETE YOUR DISCUSSION.
AP Biology Unit 3
Essay #3
DISCUSS THE KREBS CYCLE AND OXIDATIVE PHOSPHORYLATION.
SPECIFICALLY ADDRESS ATP AND COENZYME PRODUCTION, THE
LOCATION WHERE THESE BIOSYNTHETIC PATHWAYS OCCUR, AND
CHEMIOSMOTIC THEORY.
AP Biology Unit 3
Essay #4
Organisms capture and store free energy for use in biological processes. Each of the
following parts plays a role in the transfer of energy.
a. Describe how a photosystem converts light energy to chemical energy.
b. Explain how glycolysis releases free energy from glucose.
c. Describe the role of water in both cellular respiration and photosynthesis.
AP Biology Unit 3
Essay #5
An experiment was conducted to measure the reaction rate of the human salivary enzyme
amylase. Ten mL of a concentrated starch solution and 1.0 mL of amylase solution were
placed in a test tube. The test tube was inverted several times to mix the solution and then
incubated at 25°C. The amount of product (maltose) present was measured every 10 minutes for
an hour. The results are given in the table below.
Time (minutes)
Maltose Concentration (uM)
0
10
20
30
40
50
60
0
5.1
8.6
10.4
11.1
11.2
11.5
(a) Graph the data and calculate the rate of the reaction for the time period
0 to 30 minutes.
(b) Explain why a change in the reaction rate was observed after 30 minutes.
(c) Draw and label another line on the graph to predict the results if the concentration of
amylase was doubled. Explain your predicted results.
(d) Identify TWO environmental factors that can change the rate of an enzyme-mediated
reaction. Discuss how each of those two factors would affect the reaction rate of an enzyme.