Cellular respiration

1. LIGHT DEPENDENT
REACTION
LIGHT INDEPENDENT
REACTION/CALVIN
CYCLE
RAW MATERIALS
PRODUCTS
LOCATION of the
REACTION
(grana/stroma)

2. How do plants
and other
organisms used
up the chemical
energy stored
in sugar?

3. CELLULAR
RESPIRATION

4. Cellular Respiration
Occurs in the mitochondrion
The outer membrane
encloses the mitochondrion
The inner membrane folds
back and forth across the
interior is known as cristae

5. • The function of the mitochondrion may be
compared to a
• . Both are machines that release
energy from fuel.
• In the mitochondrion, the energy lost as heat is
less. Here, the combination of sugar with
oxygen is slow and occurs in several steps.
• The sugar molecules breaks down little by little
and the energy released is trapped at once in the
ATP molecule. Thus, not much energy is lost or
jeepney
engine

6. Three major reactions of the complex
process of respiration
• 1. Glycolysis ( occurs in the
cytoplasm)
• 2. Krebs Cycle ( occurs in the liquid
part of the mitochondrion)
• 3. Electron flow along the
respiratory chain (occurs in the

8. Glycolysis
• Takes place in the cytoplasm
of the cell.
• In a series of reactions,
glucose is broken down into
pyruvate (C3- a molecule
with Carbon atoms)
• Energy is released and
trapped in 2 molecules of
ATP by substrate-level
phosphorylation
• NAD+ is reduced to NADH
which carries the electrons
to electron transport chain
at the cristae

9. •Pyruvate
moves into the
mitochondrion
•Glycolysis
occurs
whether O2 is
present or not.

10. Krebs Cycle – by Hans Krebs in 1930

11. Krebs Cycle
•Takes place in the liquid part of
the mitochondrion.
•Acetyl coenzyme A ( acetyl
coA) which is formed from
pyruvate enters the cycle and
performs a series of reactions
to produce 2 molecules of CO2
•Carbon dioxide leaves the cell,
and 2 molecules of ATP is also
released again by substrate
level-phosphorylation

12. Krebs Cycle
• A pair of electrons is transferred
from the remaining two-carbon
fragment to NAD+ to form NADH
and the FAD to FADH2
• NADH and FADH the Hydrogen
carrier molecules passes into the
cristae where the third major
reactions occurs.
• Each cycle produces 2CO2, 2ATP,
3NADH, and FADH2 (Flavin
Adenine Dinucleotide) by
substrate-level phosphorylation,
per acetyl CoA.

13. Electron flow along the
respiratory chain
• FADH and NADH ( hydrogen carrier
molecules) breaks down into hydrogen
and electrons.
• The electrons flow from one electron
acceptor to another.
• The movement of electrons along the
electron transport chain does contribute to
chemiosmosis (coupling of the redox
reactions of the electron transport chain
to ATP synthesis) and ATP synthesis.
• As the electrons flow, energy is released
forming a total of 34 ATP molecules.
• The last electron acceptor is oxygen
which finally forms water with hydrogen

15. Differences between Photosynthesis and Cellular
Respiration
• Photosynthesis utilizes sunlight to produce food molecules.
• Cellular respiration utilizes glucose molecules to obtain energy-
storing ATP molecules.
• Photosynthesis takes place in plant leaves containing the
chlorophyll pigment.
• Cellular respiration takes place in the cytoplasm and
mitochondria of the cell.
• Photosynthesis uses water, sunlight, and carbon dioxide from the
atmosphere to create glucose molecules, and releases oxygen as
a by-product.
• Cellular respiration uses glucose molecules and oxygen to
produce ATP molecules, water and carbon dioxide as the by-
product.

16. • Photosynthesis takes place only when there is sunlight.
• Cellular respiration always occurs.
• Photosynthesis involves conversion of one type of energy into
another: light energy into chemical energy.
• Cellular respiration involves using that chemical energy and
breaking it down to release energy.
• Photosynthesis takes place in two stages of light reactions and dark
reactions.
• Cellular respiration involves aerobic and anaerobic respiration.
• Photosynthesis occurs only in plants and some bacteria.
• Cellular respiration takes place in all types of living organisms.

17. Equation of Aerobic Cellular Respiration
Glucose + Oxygen ➜ Carbon dioxide + Water +
Energy Released (ATP)
C6H12O6 + 6O2 ➜ 6H2O + 6CO2 + 38 ATP

18. Difference between a Chloroplast and Mitochondrion

19. Assessment:
1. Name the starting materials of respiration
2. Which major reactions uses each of these
starting materials?
3. Name the end products of respiration
4. Which major reactions forms each of these end
products?
5. In which reaction are ATP molecules produced?
6. Which reaction produces the greatest number of

20. The energy source of the Cell
• The ATP molecule is the energy source of the cell
consisting of Adenosine and three Phosphates
• Energy is stored in food molecules such as sugars,
starch and fats.
• Everytime the cell needs energy, it “withdraws” the
energy from the food molecules through the process
of respiration done in the mitochondrion.
• The process of respiration which produces 38 ATP
molecules from one glucose molecule can supply the
cell with 252 kilocalories of energy

21. Our Body needs
• Those who want to lose weight are advised to watch their calories.
Calories is a unit of heat. It is a measure of the amount of energy in
food.
• The main source of energy for man are carbohydrates and fats.
• Excess food is stored as fat.
• Some people who do not have anything to eat use the stored
energy in their bodies such as the liver , muscles and various
organs.
• When all the stored energy is used up the body starts breaking
down the proteins of the muscles which is the last food reserve.

22. • Respiration is the process through which energy is
released by breaking down glucose in the body.
• The energy produced is used by the body for various
purposes including working the muscles, keeping
body temperature constant, allowing chemical
reactions to take place, sending messages
throughout the body, etc.
• There are two types of respiration that happen
within all living things: Aerobic Respiration and
Anaerobic Respiration.

23. • Aerobic respiration is the process of
breaking down glucose using oxygen.
• The cells use glucose and oxygen to
produce carbon dioxide, water and
energy.
• This energy produced is then reserved
until required by the body.

24. • The released energy is used to make a
special energy molecule called Adenosine
triphosphate (ATP). ATP is where the energy
is stored for use later by the body.
• The process is pretty much the same for
almost all living things but is reversed in
plants because in plants it uses carbon
dioxide and water to produce glucose and

25. Anaerobic Respiration
• At rest, our body works with aerobic respiration, but there
are many times where oxygen is not available and yet the
cell needs to survive.
• In this case the cell performs Anaerobic Respiration(
breaking down glucose without Oxygen)
• In humans, this event occurs when a person performs
extraneous exercises.
• When doing an intense workout, the lungs and heart cannot
pump blood and oxygen fast enough to keep up with the
requirements of the cells. When this happens, the body
cannot simply stop making energy.

26. In such an event during anaerobic respiration:
• The body breakdown glucose by using catalysts such
as nitrate.
• These release a by product of lactic acid and energy.
• glucose lactic acid + energy
• The lactic acid causes the muscles to tire quickly
producing fatigue in the body and can even cause
cramps. Hence, the vigorous exercise cannot be
maintained for more than a few minutes.
nitrate

27. • The body needs to consume more oxygen in
order to breakdown the lactic acid inside the
body; this is known as oxygen debt.
• In plants, the process is a little different.
When glucose is broken down in plants
using anaerobic respiration, it produces a by
product of ethanol, carbon dioxide and
energy.

28. Difference between Aerobic & Anaerobic Respiration
Aerobic Respiration Anaerobic Respiration
Definition
Uses oxygen to breakdown
glucose in the body
Uses a respiratory electron
transport chain but does not use
oxygen as the electron
acceptors.
Cells that use it
Aerobic respiration occurs in
plant and animal cells
Anaerobic respiration occurs in
bacteria, yeasts, some
prokaryotes, erythrocytes (red
blood cells), and in muscle cells.
Lactic Acid Does not produce lactic acid Produces lactic acid

29. Aerobic
Respiration
Anaerobic Respiration
By
Product
s
Carbon dioxide, water,
energy
• Lactic acid + energy in animals
• Ethanol + carbon dioxide + energy
in Plants
Equatio
n
C6H12O6+ O2 CO2 + H2O • C6H12O6 2C3H6O3 + energy
• C6H12O6 2C2H5OH +
2CO2+energy
Locatio
n
Begins in cytoplasm
and continues to
mitochondria
In cytoplasm