Transcript Cellular Respiration

Announcements
• Vocabulary Quiz Tomorrow or Content
Quiz Monday?
• Exam Next Thursday
Agenda
• Exams
• IQ # 1
• 9.1a Lecture
Grade Distribution
Scale Grade
41- 46+ - A 37- 40 - B 32 – 36 - C 28 - 31 - D 0 - 28 - F -
# of people
15 people
8 people
6 people
6 people
1 people
IQ # 1
• What is a Calorie? How many Calories are released
when 1 gram of glucose is burned?(p. 221)
• What is Glycolysis? Does it release a lot of
energy?(p. 221, 223)
• What is Cellular Respiration? What is the chemical
formula? How is this similar to photosynthesis?
• Draw the Mitochondria, label all parts. (p. 221, fig
9.1)
CHAPTER 9
CELLULAR
RESPIRATION
CHAPTER 9: CELLULAR RESPIRATION
9-1 Chemical Pathways
A. Chemical Energy and Food
energy
 Food serves as a source for _________.
3,811 calories.
 1g of glucose (C6H12O6) releases _______
 calorie= the amount of energy needed to raise the
temperature of 1g of water 1°C.
 We gradually release the energy of glucose and other
compounds (fats, proteins, and carbohydrates).
 The process begins with a pathway called__________.
glycolysis.
 If oxygen is present,
glycolysis leads to cellular respiration (Krebs cycle and
electron transport chain). (process = aerobic)
 If oxygen is not present,
glycolysis leads to fermentation. (process = anaerobic)
Section 9-1
Chemical Pathways
Glucose
Glycolysis
Krebs
cycle
Fermentation
(without
oxygen)
Electron
transport
1. Alcohol
or
2. Lactic
acid
B. Overview of Cellular Respiration
Cellular Respiration=
the process that releases energy by breaking down
glucose and other food molecules in the presence of
oxygen.
mitochondria is the
Remember: the ____________
organelle known as the “powerhouse”- the site
where energy is produced.
Cellular respiration takes place in the mitochondria.
The equation for cellular respiration=
6O2 + C6H12O6
6CO2 + 6H20 + Energy
 ________
Glucose stores large amounts of energy. The
cell can’t release all the energy at one time. It is too
much for the cell to handle.
 3 main stages of cellular respiration:
1. Glycolysis (glycol= sugar; lysis=break apart)
2. Krebs Cycle
3. Electron Transport Chain (ETC)
Section 9-2
Flowchart
Cellular Respiration
Glucose
(C6H1206)
+
Oxygen
(02)
Glycolysis
Krebs
Cycle
Electron
Transport
Chain
Carbon
Dioxide
(CO2)
+
Water
(H2O)
Respiration: An Overview
Section 9-1
Mitochondrion
Electrons carried in NADH
Pyruvic
acid
Glucose
Glycolysis
Krebs
Cycle
Electrons
carried in
NADH and
FADH2
Electron
Transport
Chain
Mitochondrion
Cytoplasm
2
2
34
http://scholar.hw.ac.uk/site/biology/activity3.asp
C. Glycolysis=
the process in which one molecule of glucose is broken
in half, producing two molecules of pyruvic acid, a 3carbon compound.
This pathway does not require oxygen
 Prokaryotes depend on this process alone for ATP.
Section 9-1
Glucose
2 Pyruvic
acid
PGAL
(Phosphoglyceraldehyde)
To the electron transport
chain
1. ATP Production
2 ATP
 Use__
4 ATP
 Makes __
2 ATP
 Net gain is __
2. NADH Production
 NAD+ (nicotinamide adenine dinucleotide) is an
Electron carrier
_____________.
NADH (an electron
 NAD+ accepts electrons to make ______
carrier).
2 NADH are produced.
 In glycolysis, ________
 NADH will carry its’ electrons to
the electron transport chain.
3. Overall, Glycolysis produces
 2 ATP “Net” (energy molecules)
 2 NADH (electron carriers)
 2 Pyruvic Acid (3-C sugars)
9-1 [continued...] Fermentation
 What happens when oxygen is not present?
Anaerobic process
 Fermentation=
release of energy from food molecules by producing ATP
in the absence of oxygen.
 Glycolysis still occurs in the cytoplasm producing pyruvic acid.
 The pyruvic acid can go through one of two types of
fermentation:
Alcoholic Fermentation
1. __________
Occurs in yeast cells and other microorganisms.
Pyruvic acid + NADH → alcohol + CO2 + NAD+
Important to bakers and brewers.
CO2 released causes bread to rise
____
2. ___________
Lactic Acid Fermention
Section 9-1
Glucose
Pyruvic
acid
Lactic acid
 Produced in our muscle cells when oxygen levels are too low
Lactic Acid causes the burning feeling.
 Build up of _________
NAD+ is regenerated to keep running glycolysis.
 ______
 Prokaryotes are used to make food because they do
produce lactic acid. Some examples:
-cheese
-yogurt
-kimchi
-sauerkraut
-sour cream
-buttermilk
-pickles
Section 9-1
Chemical Pathways
Glucose
Glycolysis
Krebs
cycle
Fermentation
(without oxygen)
Electron
transport
Alcohol or
lactic acid
http://www.qcc.cuny.edu/BiologicalSciences/Faculty/DMeyer/respiration.html
COMPARISON OF FERMENTATION TO
CELLULAR REPIRATION
Lactic Acid
glucose
Alcoholic
glucose
Cellular respiration
glucose
glycolysis
(pyruvic acid)
glycolysis
(pyruvic acid)
carbon dioxide
carbon dioxide
lactic acid
alcohol
water
2 ATP
2 ATP
38 ATP (net 34)
glycolysis
(pyruvic acid)
9-2 The Krebs Cycle and Electron Transport
A. The Krebs Cycle (aka: Citric Acid Cycle)
1. Pyruvate
(pyruvic acid)
oxidation
2. Energy Extraction
Hans Krebs
Named after __________.
Occurs in the Mitochondria (therefore this process only
Eukaryotes
occurs in __________)
Krebs cycle= process where pyruvic acid is broken
down into carbon dioxide in a series
of energy-extracting reactions.
Krebs cycle begins when pyruvic acid enters
mitochondria.
1. Pyruvate (pyruvic acid) Oxidation
 In this process, it produces the following for glucose:
2 acetyl-CoA (2-C sugar)
2 NADH (electron carriers)
2 Carbon dioxide (waste product)
2. Energy Extraction
 Acetyl CoA ( 2-C ) binds with a Oxaloacetic acid
( 4-C ) molecule to form Citric Acid ( 6-C )...Hence,
the name Citric Acid Cycle.
 Citric Acid is oxidized (by NAD+ and FAD) through a
series of reactions that finally produces Oxaloacetic Acid
again.
2 times per Glucose
 The Krebs Cycle runs __
molecule. (Once per pyruvic acid.)
 This process produces (per glucose molecule):
6 NADH (electron carriers-go to ETC)
- ___
2 FADH2 (electron carriers-go to ETC)
- ___
2 ATP (energy-used by cell to do work)
- ___
- ___
4 CO2 (waste product- gets exhaled)
B. Electron Transport (ETC)
The Electron Transport Chain=
process
Section 9-2 that uses the high-energy electrons
from the Krebs cycle to convert ADP into ATP.
Electron Transport
Hydrogen Ion Movement
Channel
Mitochondrion
Intermembrane
Space
ATP synthase
Inner
Membrane
Matrix
ATP Production
If oxygen is not present:
Fermentation
Pyruvic
acid
If oxygen is
present:
Cellular
Respiration
Cytoplasm
Pyruvic
acid
PGAL
To ETC
Lactic acid
(or Alcohol
& CO2 )
Cell Respiration Drawing
Instructions
• Using template, draw in the steps of cell
respiration
– Glycolysis/fermentation(p.223 & 225)
– Pyruvic Acid Oxidation/Citric Acid
production(p.227)
– Kreb’s Cycle (Citric Acid Cycle(p.227)
– Electron Transport Chain(p.228)
• Include the totals for each reaction(p.229)

The Process:
A. Electron Transport
1. Glycolysis and the Krebs Cycle deliver their
NADH
________
and _______
FADH2 to the matrix of the
mitochondria.
2. NADH and FADH2 donate their high energy electrons
to the ETC.
NADH →
NAD+
FADH2→
FAD
(recycled)
+
+
H+
+
e-
2H+
+
2e-
(go to intermembrane space)
(passed to ETC)
3. Electrons are passed from carrier to carrier in the
inner membrane.
*(in prokaryotes the ETC is in the cell membrane)
Oxygen is the
4. At the end of the chain, ________
final electron acceptor.
5. Oxygen uses the electron to
covalently bond with hydrogen forming
water. (oxygen is reduced)
Interactive link: Use ETS and Making ATP
http://www.sp.uconn.edu/~terry/Common/respiration.html
IQ # 2 – 8.2
1. Summarize each of the steps in the Krebs
Cycle in your own words (p. 226-227)
2. Summarize each of the steps of the electron
transport chain in your own words (p. 228-229)
3. What is the difference between short term and
long term energy (p. 230-231)
Announcements
• Exam – Thursday
• Extra Credit – Wednesday (9.1 & 9.2)
• HOMEWORK: 9.2 Section Assessment
Agenda
• IQ # 2 (Check Homework: Flashcards and
9.1 section assessment)
• Lecture/Drawing Activity
• Time Permitting, finish remaining slides
Announcements
•
•
•
•
Exam – Thursday
Extra Credit – Wednesday
Thursday –lunch answering questions
Homework – Review Sheet
Agenda
•
•
•
•
•
Finish Mitochondria Drawing
Finish Lecture
5 minute video
Review IQs
Review Homeworks
B. Hydrogen Ion Movement
1. As the high energy electrons are transported down the
chain, their energy is used to push H+ from the matrix,
through the inner membrane, to the
intermembrane space.
2. It takes 2e- to move 1H+
intermembrane space becomes (+) positively
3. The _____________
charged.
4. The _______
matrix becomes (-) negatively charged.
C. ATP Production
1. Hydrogen ions return to the matrix through the enzyme
ATP synthase.
2. As Hydrogen passes, the enzyme
grabs a phosphate and attaches it to ADP to become ATP.
D. This process produces:
- 34 ATP
-
water
C. The Totals Per Glucose molecule
3 ATP
***note: each NADH produces __
2 ATP
each FADH2 produces __
Click on ATP synthesis and play the first one only
http://www.wiley.com/legacy/college/boyer/0470003790/animations/electron_transport/electron_transport.htm
LOCATION
ATP
NADH
FADH2
BYPRODUCTS
cytoplasm
2
2
0
------
KREBS CYCLE:
Pyruvate oxidation
→
matrix
0
2
0
Carbon
dioxide
Energy Extraction
→
matrix
2
6
2
Carbon
dioxide
Inner
Membrane
(Cristae)
34
0
0
water
GLYCOLYSIS
ELECTRON
TRANSPORT
CHAIN
TOTALS (net)
36
2
-2 ATP (transport of pyruvic acid into mitochondria)
D. Energy and Exercise (refer to activity sheet)
E. Comparing Photosynthesis and Cellular Respiration
Photosynthesis
Function
Cellular Respiration
Energy Capture
Energy Release
Chloroplasts
Mitochondria
H2O and CO2
C6H12O6 and O2
C6H12O6 and O2
H2O and CO2
Location
Reactants
Products
Equation
6H2O + 6CO2 → C6H12O6 + 6O2
C6H12O6 + 6O2 → 6H2O + 6CO2
Comparing Photosynthesis and
Cellular Respiration
Photosynthesis
Cellular Respiration
Food synthesized
Energy from sun stored in glucose
Food broken down
Energy of glucose released
Carbon dioxide taken in
Carbon dioxide given off
Oxygen given off
Oxygen taken in
Produces sugars from PGAL
Produces CO2 and H2O
Requires light
Does not require light
Occurs only in presence of
chlorophyll
Occurs in all living cells
IQ # 1
• What is a Calorie? How many Calories are released
when 1 gram of glucose is burned?(p. 221)
• What is Glycolysis? Does it release a lot of
energy?(p. 221, 223)
• What is Cellular Respiration? What is the chemical
formula? How is this similar to photosynthesis?
• Draw the Mitochondria, label all parts. (p. 221, fig
9.1)
IQ # 2 – 8.2
1. Summarize each of the steps in the Krebs
Cycle in your own words (p. 226-227)
2. Summarize each of the steps of the electron
transport chain in your own words (p. 228-229)
3. What is the difference between short term and
long term energy (p. 230-231)
California State Standards


1g. Students know the role of the
mitochondria in making stored chemicalbond energy available to cells by
completing the breakdown of glucose to
carbon dioxide.
1i* Students know how chemiosmotic
gradients in the mitochondria and
chloroplasts store energy for ATP
production.
Warm-up Section 9-1
► What
is cellular respiration?
► Draw
a picture of a cell and label where
glycolysis, krebs cycle, and ETC occur.
► What
happens during the process of
glycolysis?
Warm up section 9-2
► What
happens during the Krebs cycle.
► How
are high energy electrons used by the
electron transport chain?
► What
pathways are taken by pyruvic acid if
oxygen is not available?