Unit 5 Part 2 Notes-CP

Cellular Respiration

Standards

• H.B.2: The student will demonstrate the understanding that the essential functions of life take place within cells or systems of cells.– H.B.2A.1 Construct explanations of how the structures of

carbohydrates, lipids, proteins, and nucleic acids (including DNA and RNA) are related to their functions in organisms.

• H.B.3: The student will demonstrate the understanding that all essential processes within organisms require energy which in most ecosystems is ultimately derived from the Sun and transferred into chemical energy by the photosynthetic organisms of that ecosystem– H.B.3A.4 Develop models of the major inputs and outputs of cellular

respiration (aerobic and anaerobic) to exemplify the chemical process in which the bonds of molecules are broken, the bonds of new compounds are formed and a net transfer of energy results

– H.B.3A.5 Plan and conduct scientific investigations or computer simulations to determine the relationship between variables that affect the processes of fermentation and/or cellular respiration in living organisms and interpret the data in terms of real-world phenomena.

Chemical Energy and Food

• Organisms get energy from food

• Energy stored in food is expressed in calories

– calorie: amount of energy needed to raise the

temperature of 1 gram of water 1 degree C

– Calorie - on food labels is actually 1000 calories or a

kilocalorie)

– Carbohydrates and proteins = ~4000 calories (4

Calories per gram)

– Fats = ~9000 calories (9 Calories per gram)

• Food is broken down gradually to get energy in

cellular respiration

Chemical Energy and Food

• Any food (organic) molecule, including

carbohydrates, fat/lipids, and protein can be

broken down into smaller molecules and used as

energy to make ATP

Cellular Respiration Overview

• Cellular Respiration – process that releases energy

from food in the presence of oxygen

C6H12O6 + 6O2 6CO2 + 6H2O + ATP

SUGAR and OXYGEN makes CARBON DIOXIDE and WATER and ENERGY

Carbon Dioxide Water

Sugar/Glucose

Oxygen

Mitochondria Structure

• Most of cellular respiration

happens in Mitochondria

• Outer membrane

• Folded inner membrane

(folds called cristae)

• Inside of inner membrane

is called matrix

• Intermembrane space

between the 2 membranes

Intermembrane

space

Cellular Respiration Overview

3 Stages

• 1. Glycolysis

– In the cytoplasm

– Glucose is split

– Little bit of ATP made

– Anaerobic – NO OXYGEN NEEDED

• 2. Krebs cycle

– In the mitochondria

– Little bit of ATP made

– CO2 produced

– Aerobic – OXYGEN NEEDED

• 3. Electron Transport Chain

– In the mitochondria

– LOTS of ATP made

– H2O produced

– Aerobic – OXYGEN NEEDED

Photosynthesis and Cellular

Respiration Connection

• Photosynthesis removes CO2

from atmosphere; Cellular

respiration puts it back

• Photosynthesis releases

oxygen into the atmosphere;

Cellular respiration uses that

oxygen to release energy from

food

Cellular Respiration:

Stage 1 - Glycolysis

• In cytoplasm

• Anaerobic – No O2 required

• 1 Glucose 2 Pyruvic acid

– 2 Pyruvate will go to Krebs cycle

• 2 ATP needed, but 4 come out– Net gain of 2 ATP

• 2 NAD+ become 2 NADH and

carry electrons to the Electron

Transport Chain (stage 3)

• Fast process

Cellular Respiration:

Stage 2 – The Krebs Cycle

• In mitochondria (matrix)

• Aerobic – O2 required

• The pyruvic acid, produced by glycolysis, travels to

the mitochondria where it is broken down in a cycle

of chemical reactions, from which carbon dioxide

and energy (used to form a small number of ATP

molecules – 2 ATP) are released.

• The main product of the Kreb’s cycle are energy

carrying molecules that get sent on to the next

stage.

Cellular Respiration:

Stage 3 – Electron Transport Chain

• Inner mitochondrial membrane

• Aerobic – O2 Required

• The electron transport chain is a series of chemical

reactions in which energy is transferred to form a

large number of ATP molecules (up to 34 ATP).

• At the end of the chain oxygen enters the process

and is combined with hydrogen to form water.

Cellular Respiration: The Totals

• ATP produced

– Glycolysis: 2

– Krebs Cycle: 2

– ETC: 32

– 36 ATP per Glucose

• This 36 ATP is less than

40% the actual energy in

glucose

– The rest is lost as heat

Fermentation

• Fermentation allows organisms to get energy from

food when oxygen is not available

• Cytoplasm of cells

• Happens after Glycolysis

– How much ATP from glycolysis?

Fermentation

• Cells convert NADH made in glycolysis back into

electron carrier NAD+

• Allows glycolysis to keep making ATP

• Fermentation makes NO ATP

Fermentation

• 2 Types– Alcoholic Fermentation

– Lactic Acid Fermentation

Fermentation

• Alcoholic Fermentation

– Yeast and some microorganisms

– Produces ethyl alcohol and CO2

– Used to make alcoholic beverages and bread rise

Pyruvate + NADH Alcohol + CO2 + NAD+

Fermentation

• Lactic Acid Fermentation

– Most organisms including humans (muscle cells)

– Used in cheese, yogurt, sour cream, pickles, sauerkraut

Pyruvate + NADH Lactic acid + NAD+

Energy and Exercise

• Human body has 3 sources of ATP– ATP stored in muscles

– ATP via lactic acid fermentation

– ATP via cellular respiration

• Quick bursts of energy

– Stored ATP

– lactic acid fermentation

• Long-term energy (longer than 90 seconds)

– Cellular respiration

• Increase in respiratory rate, even after exercise is to help

rid the body of lactic acid and replace oxygen deficit