A. chloroplast B. photosynthesis C. cellular respiration D. glucose E. fermentation

1. A. chloroplast B. photosynthesis C. cellular respiration D. glucose E. fermentation F. chemical energy G. mitochondria ____ 1. To stay alive, a cell must be able to release the ____________ that is stored in a molecule's bonds. ____ 2. ____________ is the process by which plants produce glucose and oxygen. ____ 3. A major energy source for most cells is a sugar molecule called ____________. ____ 4. Cells use oxygen to release the energy in glucose during ____________. ____ 5. Cellular respiration takes place in a cell's ____________. ____ 6. If a muscle cell does not have enough oxygen, it can still release energy through the process of ____________.

2. A. chloroplast B. photosynthesis C. cellular respiration D. glucose E. fermentation F. chemical energy G. mitochondria ____ 1. To stay alive, a cell must be able to release the ____________ that is stored in a molecule's bonds. ____ 2. ____________ is the process by which plants produce glucose and oxygen. ____ 3. A major energy source for most cells is a sugar molecule called ____________. ____ 4. Cells use oxygen to release the energy in glucose during ____________. ____ 5. Cellular respiration takes place in a cell's ____________. ____ 6. If a muscle cell does not have enough oxygen, it can still release energy through the process of ____________. 1. F. chemical energy 2. B. photosynthesis 3. D. glucose 4. C. cellular respiration 5. G. mitochondria 6. E. fermentation

5. 2.1: Chemical reactions take place inside cells 2.2: Cells capture and release energy 2.3: Materials move across the cell’s membranes Chapter 2: How Cells Function Will learn: -why cells need energy -How energy is captured and stored -How plants and animals get energy Have already learned: -the cell is the basic unit of all living things -Plant cells and animal cells have -similarities and differences

6. All cells need energy • Animal cells, plant cells, bacteria cells, unicellular organisms: ALL need energy • Animals get it from food • Plants get it from the sun • Type of energy = chemical energy! • Cells must release the chemical energy stored in bonds (between atoms) in order to stay alive • Cells release chemical energy from glucose (sugar molecule)

7. All cells need energy • Muscle cells  • release chemical energy from glucose to move legs  • More running, more glucose needed • Energy from? • food! • For plants: • Sunlight + water + CO2 glucose + O2

8. Some cells capture light energy • Source of ALL energy? • Ultimately…the SUN! • Photosynthesis – process that plants cells use: • Energy from sunlight into chemical energy • Takes place in plant cells that have chloroplasts • Chloroplasts contain chlorophyll • Chlorophyll absorbs light • Starting materials: carbon dioxide (air) + water (soil) • The process: Materials enter chloroplasts + energy (sunlight) • The products:  Glucose and Oxygen! Some glucose is linked together to build large carbohydrates: • stored as starch

9. All cells release energy • Glucose and other sugars are “cell food” • Glucose is stored as glycogen or starch • Must be broken down to use as energy • Break the bonds of sugar – release energy! • Two ways: • Respiration • Requires oxygen • Release more usable energy than fermentation • Fermentation • Does not require oxygen

10. Cellular Respiration • Think: reverse of photosynthesis…occurs in mitochondria (chloroplasts) • Starting materials: oxygen and sugar • USE oxygen to RELEASE energy stored in sugars, such as glucose • Gain oxygen and sugars • The process: • Glucose in cytoplasm is broken down into smaller molecules, releasing some energy • Molecules move to mitochondria and oxygen enters cell (and moves to mitochondria) • The smaller molecules are further broken down • Hydrogen released (combines with oxygen to make water) • The products • Energy, carbon dioxide, water (starting products of …) • Some of this energy is transferred to other molecules, so is released as heat

12. Fermentation • Cells releasing energy withOUT oxygen • When cells first break glucose into smaller molecules, a small amount of energy is released • With oxygen…cellular respiration would continue in the mitochondria • Without oxygen…fermentation continues in the cytoplasm • Two types: Alcoholic and Lactic Acid Fermentation • Both start with small molecules made from sugars • Next reactions occur producing either alcohol and carbon dioxide OR lactic acid • In both, a small amount of energy is then released

13. Fermentation • Examples: • Bread: mix flour, milk, and sugar, with a microorganism yeast • Without oxygen, yeast converts the sugar into alcohol and carbon dioxide (CO2) – bubbles of CO2 gas form in the dough causing it to rise…alcohol evaporates, the yeast is killed, and CO2 makes the bread spongy • Yogurt, cheese, sourdough bread • Lactic acid bacteria convert the sugars found in milk • Sourdough bread: acidity changes  sour flavor • Yogurt and cheese: milk partially solidifies: creamy texture of yogurt…if fermentation continues  cheese

14. Energy and exercise • Some cells (and organisms) can release energy using either cellular respiration or fermentation • At rest, muscle cells store both energy and oxygen • During exercise all the energy and oxygen may be used up • Fermentation is then used to break down the sugars • Less energy than with cellular respiration • Waste product: lactic acid = burns! • Breath hard to replace used oxygen • Muscles stop hurting and build back up oxygen and energy levels

17. http://www.cambridgestudents.org.uk/subjectpages/biology/igcsebiology/igcsebiologysimulationshttp://www.cambridgestudents.org.uk/subjectpages/biology/igcsebiology/igcsebiologysimulations • Grow a plant