Where does the majority of the mass go from the food you eat?

The majority of the mass from food you eat gets exhaled as carbon dioxide!!

How do we know?

Exercise and Pulse

• Predict what happens to your pulse when you exercise.

• Explain why your pulse increases when you exercise.

• Summarize what your body uses oxygen for.

What do we need energy for?

• All organisms need energy in order to carry out their every day functions.– Such as breathing, walking, running, eating, thinking,

growing, etc.

ENERGY

What form of energy do we make?

2009-2010

ATP

Energy in Biology

Adenosine TriPhosphate

Every organism needs ATP!

2 cellular processes make ATP • Review: Photosynthesis – Done by plants – Happens in the Chloroplast – Makes ATP from sunlight– Some ATP is used for food for the plant

• Today:Cellular Respiration – Done by all living things (in some form)– Happens in the Mitochondria – Makes ATP from breaking down food

Energy Reactions

• Cellular Respiration – C6H12O6 + 6 O2 6 H2O + 6 CO2 + 36 ATP

• Photosynthesis – 6 CO2 + 6 H2O + Sunlight C6H12O6 + 6 O2

Which are reactants and which are products?

Checkpoint

• Using the equations for cellular respiration and photosynthesis, justify why plants need to make glucose through photosynthesis.

• Cellular Respiration – C6H12O6 + 6 O2 6 H2O + 6 CO2 + 36 ATP

• Photosynthesis – 6 CO2 + 6 H2O + Sunlight C6H12O6 + 6 O2

Predict what types of cells in your body would contain many mitochondria.

Cellular Respiration • Purpose: to break down glucose

• Can be done with or without oxygen –With Oxygen: Aerobic Respiration –Without Oxygen: Anaerobic Respiration

Glucose Energy

Location of Reactions

Cellular Respiration: occurs in the mitochondria of cells

Cellular Respiration – 3 Steps C6H12O6 + 6 O2 6 H2O + 6 CO2 + 36 ATP

• 1. Glycolysis –Happens in the

cytoplasm –Glucose is split in half–Makes 2 ATP

• 2. Kreb’s Cycle–Happens in Mitochondria–Breaks down Glucose further–Makes 2 ATP

Cellular Respiration – 3 Steps C6H12O6 + 6 O2 6 H2O + 6 CO2 + 36 ATP

• Electron Transport Chain–Happens in Mitochondria–Uses O2 Gas–Makes 32 ATP

Cellular Respiration – 3 Steps C6H12O6 + 6 O2 6 H2O + 6 CO2 + 36 ATP

Cellular respiration • Aerobic (with oxygen)• Cellular Respiration• Result: 36 ATP, 6 water, 6

oxygen molecules• All eukaryotic life does this

With O2 present

• Anaerobic (without oxygen)• Fermentation• Result: 2 ATP, bigger molecules

(varies with type)• All prokaryotes do this and

some eukaryotes do when stressed

With O2 absent

Cellular respiration: Fermentation• 2 Types of Fermentation

Lactic Acid fermentation

Higher animals do this in muscles

Result: 2 ATPs and lactic acid

(may cause muscle cramps)

Alcoholic fermentation

Yeast cells and bacteria do this

Result: 2 ATP, ethyl alcohol, carbon dioxide (used in

bread and beer/wine making)

Energy Tally• 36 ATP for aerobic vs. 2 ATP for anaerobic

– Glycolysis 2 ATP

– Kreb’s 2 ATP

– Electron Transport 32 ATP Total: 36 ATP

Do we think we always make this exact number of ATP?

Back to the equation….

– C6H12O6 + 6 O2 6 H2O + 6 CO2 + 38 ATP

– C6H12O6 (food we eat)+ 6 O2 (air we breathe) 6 H2O (liquid waste) + 6 CO2 (what we exhale) + 38 ATP (no mass)

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