Download Photosynthesis and Cellular Respiration

CELLULAR RESPIRATION
HARVESTING ENERGY FROM FOOD
Autotrophs are organisms such as a plant
that makes its own food. For example,
during photosynthesis plants use the
sun's energy to convert water and carbon
dioxide into sugars. Autotrophs are also
called producers.
Heterotrophs are organisms that cannot
make their own food, such as humans,
meaning "other eaters." Heterotrophs
are also called consumers.
QUESTION

What happens to all this food once it is made
by plants?
WHAT IS CELLULAR RESPIRATION?

Cellular Respiration is the process by which
cells obtain energy from glucose.

Cells break down simple food molecules (sugar)
and release the energy they contain.
Energy flow occurs
through the ecosystem
The products of
photosynthesis are the
chemical ingredients for
cellular respiration, while the
products of cellular
respiration are the chemical
ingredients for
photosynthesis.
Chemical Energy
Just like the molecules in gasoline and other fuels, organic compounds are a
form of potential energy called chemical energy.
The stored chemical energy of
foods such as peanuts can be
released through cellular
respiration.
Relationship of Cellular Respiration to Breathing
Cellular respiration is an aerobic process, meaning that it requires oxygen
Breathing supports cellular respiration by providing the body with oxygen
and removing carbon dioxide.
Overall Equation for Cellular Respiration
In cellular respiration, the atoms in glucose and oxygen are rearranged,
forming carbon dioxide and water. The cell uses the energy released to
produce ATP.
Cellular respiration breaks down organic molecules to yield energy
in the form of ATP
https://www.youtube.com/watch?v=M1iRxCaFjoo
HOW DOES CELLULAR RESPIRATION WORK?


1-2-3 Steps
1: The first stage takes place in the cytoplasm, and
molecules of glucose are broken down (anaerobic-no
oxygen used).

2-3: The second and third stage occurs in the
Mitochondria, and there, small molecules are broken
down into even smaller molecules (aerobic- needs
oxygen).

Energy is released at all stages = ATP
https://www.youtube.com/watch?v=JUmT24R8CyA
ATP provides the energy for cellular work
ATP: (adenosine triphosphate) main energy source that
cells use for most of their work
An ATP molecule contains potential energy, much
like a compressed spring. When a phosphate group
is pulled away during a chemical reaction, energy is
released.
The ATP Cycle
ATP is constantly recycled in your cells. Millions
of ATP molecules are used and regenerated per
second! Cellular Respiration provides chemical
energy to assemble ADP to ATP
Mitochondria
Mitochondria are found in almost all eukaryotic
cells including plant and animal cells. Its
structure is key to its role in cellular respiration.
Mitochondria
Its complex folding pattern of
membranes and spaces allows for
many sites where reactions can
occur.
Parts of the Mitochondria
• Outer membrane
• Inner Membrane
• Matrix – fluid inside
• Cristae – folds
Cellular Respiration involves Glycolysis, the Citric Acid Cycle, and
Electron Transport Chain
Stage I: Glycolysis
The first stage in breaking down a glucose molecule, called
glycolysis (splitting sugar), takes place outside the mitochondria in
the cytoplasm of the cell.
1. GLYCOLYSIS

Glycolysis
 Series
of reactions which break the glucose molecule
down into two molecules called pyruvate
 Process
is an ancient one-all organisms from simple
bacteria to humans perform it the same way
 Yields
2 ATP molecules for every one glucose
molecule broken down
 Doesn’t
require oxygen – anaerobic
Stage 2: The Citric Acid or Krebs Cycle (named after Hans Kreb)
The Krebs cycle finishes the breakdown of pyruvic acid molecules to
carbon dioxide, releasing more energy in the process. The enzymes
for the this cycle are dissolved in the fluid matrix.
CRITIC ACID OR KREB’S CYCLE

Continues to break down gluclose
 Takes
the pyruvate and breaks it down, releasing
CO2
 Production of only 2 more ATP but loads up energy
for the next stage
Stage 3: Electron Transport Chain
The final stage occurs in the inner membranes of
mitochondria. This stage yields the most ATP about 34 ATP
ELECTRON TRANSPORT CHAIN

Energy and remaining substance from the last
step is carried over to create ATP from ADP.

In this final step, energy is provided to form a
total of 34 ATP

https://www.youtube.com/watch?v=Fcu_8URp4Ac
HOW MANY ATP IN TOTAL?
Fermentation in Human Muscle Cells
When your lungs and bloodstream can't supply oxygen
fast enough to meet your muscles' need for ATP. Your
muscle cells use fermentation, to make ATP without using
oxygen.
WHAT IS FERMENTATION?
Breaking down glucose without oxygen
 Fermentation does not give off as much energy
as Cellular Respiration.

Fermentation in Microorganisms
Yeast (a microscopic fungus) is capable of both cellular
respiration and fermentation.
Fermentation in yeast produces ethyl alcohol. The carbon
dioxide that is released during fermentation creates
bubbles and pockets that make bread rise. The alcohol
evaporates during baking.
It's the carbon dioxide
that is released by yeast
that makes baked goods
rise.
Wine is the product of yeast
fermentation in fruit juice, while beer is
the product of yeast fermentation in
grain
PHOTOSYNTHESIS VS. CELLULAR RESPIRATION




Both involve the same chemical compounds, but are
the reverse processes.
Cellular Respiration produces CO2, while
Photosynthesis uses up CO2 in the atmosphere.
Cellular Respiration uses O2, but Photosynthesis
produces it.
Photosynthesis requires energy from the sun, Cellular
respiration gets energy from breaking down the
chemical bonds in sugar molecules.
ATP

Adenosine Triphosphate
CELLULAR RESPIRATION - RECAP
1.
2.
3.
4.
5.
6.
In what type of cell does cellular respiration
occur?
What is the organelle in the cell where cellular
respiration occurs?
How many parts are there to cellular
respiration?
What are the products of cellular respiration?
What are the reactants of cellular respiration?
What is the energy molecule which is produced
from this process?
ENERGY TALLY

36 ATP for aerobic vs. 2 ATP for anaerobic
 Glycolysis
2 ATP
 Kreb’s
2 ATP
 Electron
Transport
34 ATP
38 ATP
MITOCHONDRION