Cellular Respiration

download report

Transcript Cellular Respiration

Cellular Respiration


The process by which
living things release
energy stored in organic
molecules
Takes Place in 2 major
stages


Glycolysis
Oxidative Respiration
or Fermentation

Adenosine
Triphosphate
Yeast in a Bottle

Think about what is
happening in this demo
while you learn about
Cell Respiration.
Yeast in a Bottle Experiment


What affects the rate of
cellular respiration in
yeast?
Materials




Test tubes
2.5mL yeast (1/2 tbsp)
2.5mL sugar
20mL water (45 degrees
Celsius or 110 F.)
I. Glycolysis - The splitting of glucose into
2 three Carbon molecules called
Pyruvate





Occurs in cytoplasm
NAD is reduced to
NADH
CO is released
2 ATP produced
Does NOT require
OXYGEN
2

http://www.brookscole.com/chemistry_d/tem
plates/student_resources/shared_resources/ani
mations/oxidative/oxidativephosphorylation.ht
ml
II. Anaerobic vs Aerobic
A. Anaerobic (w/o O )
2

Fermentation

Process by which pyruvate
is converted into either
alcohol and CO or lactic
acid
Occurs in cytoplasm
H from NADH is
attached to pyruvate
Only 2 ATP are produced
2



B.



Aerobic (with O )
Oxidative Respiration – process by which pyruvate is
broken down to form MOST of the energy which is
supplied to plants and animals
Occurs in mitochondria
Occurs in 2 major phases
2


Krebs Cycle  2 ATP are produced
 Occurs in Matrix of Mitochondria
Electron Transport Chain  32 ATP are produced
 Occurs in Inner Membrane of Mitochondria






Each Cell uses between 1-2 billion ATP/min.
How many ATP’s are used each minute by all
100 trillion cells in the body?
1 glucose = 686 Cal
1 ATP = 7 Cal
How efficient is aerobic respiration?
How does the efficiency of your cells compare
to the efficiency of an automobile that are only
25% efficient in converting chemical energy into
mechanical energy?
Sources of Energy for contraction







Glycolysis 2 ATP
Lactic Acid Fermentation 2 ATP
Aerobic Respiration 34 ATP
Creatine Phosphate (5x more than ATP)
(donates Phosphate to ADP  ATP)
Exercise Requirements: 10 min. taps glycogen for
glucose
10-30 min. Cells use either glucose or fatty acids
(bloodstream)
Beyond 30 min.  fatty acids are primary source
Oxygen debt



The amount of oxygen necessary to support the
conversion of lactic acid to glycogen
Oxygen  lactic acid  pyruvate  ATP or
glucose  glycogen
No Oxygen  lactic acid build up
Muscle Fatigue


Inability of muscle to contract
Results from a deficit of ATP and/or accumulation
of lactic acid  lowers pH
1.
What is the function of Cellular respiration? What organisms do
this process?
2.
What are the two steps of Cellular Respiration?
3.
What are the end products of Glycolysis?
4.
Where in the cell does Glycolysis occur? (cytoplasm or
mitochondria)
5. How many energy molecules are produced from Glycolysis?
6. What are the two steps to oxidative respiration?
7. Where do both of these energy-producing steps occur within the
cell? (Cytoplasm or mitochondria)
What do you think of
when you hear
Fermentation?
What affects the rate of cellular
respiration in yeast?
Through a process called cellular respiration, the
cells of most organisms use oxygen to release the
energy that is stored in food molecules. Fungi use a
different process, called fermentation, that does
not use oxygen to release energy. During both
cellular respiration and fermentation, energy is
released when the chemical bonds that hold the
food molecules together are broken. All organisms
then use elements, such as carbon, to build their
own biological molecules. The molecules left after
these processes are waste products.
Fermentation
One of the waste products is carbon dioxide, a
molecule that contains carbon. As organisms conduct
cellular respiration or fermentation, they release waste
carbon dioxide as a gas into the atmosphere.
Photosynthetic organisms, such as plants, absorb this
carb dioxide and use it in photosynthesis. The carbon
gets incorporated into parts of the plant (for example,
as part of the starch in a potato) and may end being
consumed by yet another animal. The constant
cycling of carbon through organisms to the
atmosphere and back again is called carbon cycle.

Question: What affects the rate of cellular respiration
in yeast?

Hypothesis:

Materials:

Procedure: (step by step recipe)

Record: (data table, charts, etc)

Analyze and conclude.
What affects the rate of cell respiration in yeast?
1.
Does room temperature affect how much gas is
created by the yeast?
2.
Does the size of the container affect how much gas
is created?
3.
What water/room temperature helps the yeast create
the most gas?
4.
What "yeast food" helps the yeast create the most
gas?