Cell Energy: Photosynthesis & Respiration Chapter 5, Section 1

Today’s Learning Goals In plants, chlorophyll (found in chloroplasts) captures energy from the sun in order to make food during photosynthesis In plants, chlorophyll (found in chloroplasts) captures energy from the sun in order to make food during photosynthesis Cells release energy from food through either cellular respiration or fermentation Cells release energy from food through either cellular respiration or fermentation Why it matters: Understanding how plants & animals get energy to grow & develop is an important part of biology. Why it matters: Understanding how plants & animals get energy to grow & develop is an important part of biology.

How Does a Plant Make It’s Own Food? Plants use carbon dioxide (CO 2 ), water (H 2 O), and sun’s energy to make food. Plants use carbon dioxide (CO 2 ), water (H 2 O), and sun’s energy to make food. This is called “photosynthesis” This is called “photosynthesis” The food gives plants energy The food gives plants energy Animals get the energy stored in plants when they eat them. Animals get the energy stored in plants when they eat them.

How Do Plants Get Energy From Sun? Plants have pigments that absorb energy from light Plants have pigments that absorb energy from light Chlorophyll (found in chloroplasts) is the pigment used in photosynthesis Chlorophyll (found in chloroplasts) is the pigment used in photosynthesis

What “Food” do Plants Make? The “food” plants make is a sugar called glucose (C 6 H 12 O 6 ). The “food” plants make is a sugar called glucose (C 6 H 12 O 6 ). Glucose and oxygen (O 2 ) are made during photosynthesis. Glucose and oxygen (O 2 ) are made during photosynthesis.

How Do Organisms Get Energy From Food? Animals cannot make their own food like plants can. Animals cannot make their own food like plants can. But, BOTH plants and animals must break down (digest) food in order to get energy from it (so they can live, grow, & develop) But, BOTH plants and animals must break down (digest) food in order to get energy from it (so they can live, grow, & develop) Cells do this 2 ways: cellular respiration and fermentation Cells do this 2 ways: cellular respiration and fermentation

Cellular Respiration & Fermentation Cellular Respiration uses oxygen (O 2 ) to break down food Cellular Respiration uses oxygen (O 2 ) to break down food Fermentation does not use oxygen Fermentation does not use oxygen Cellular respiration releases more energy from food than Fermentation. Cellular respiration releases more energy from food than Fermentation. So most eukaryotes (ex: plants & animals) get their energy through cellular respiration So most eukaryotes (ex: plants & animals) get their energy through cellular respiration

Cellular Respiration Cellular Respiration = chemical process that happens in cells Cellular Respiration = chemical process that happens in cells In prokaryotes, it happens in the cell membranes In prokaryotes, it happens in the cell membranes In eukaryotes, it happens mostly in the mitochondria In eukaryotes, it happens mostly in the mitochondria

Process of Cellular Respiration Food (glucose) is broken down into CO2 and H2O and energy is released C6H12O6 + 6 O2  6 CO2 + 6 H2O + energy (ATP) This energy can be used for: Keeping a constant body temperature Storage (ATP) - to be used later for things like growth

What Do You Notice?

Check It Out! Did you notice that cellular respiration is just the opposite of photosynthesis? Did you notice that cellular respiration is just the opposite of photosynthesis?

Fermentation Happens when cells cannot get the oxygen they need for cellular respiration Fermentation is a way to get energy when oxygen isn’t available Ex: In short, fast races you might get a burning feeling in you leg muscles because of a build up of lactic acid (made during fermentation)

Pop Quiz 1) Plants use carbon dioxide (____), water (____), and the sun’s energy to make food. CO 2 and H 2 O CO 2 and H 2 O 2) What type of cell has chloroplasts? PLANT CELL 3) BOTH plants and animals must break down food in order to get ________from it. ENERGY 4) How are respiration and photosynthesis related? THEY ARE THE REVERSE (OPPOSITE) OF EACH OTHER. 5) Fermentation is a way to get energy when ______ isn’t available. OXYGEN

Today’s Learning Goals In plants, chloroplasts capture energy from the sun in order to make food during photosynthesis In plants, chloroplasts capture energy from the sun in order to make food during photosynthesis Cells release energy from food through either cellular respiration of fermentation Cells release energy from food through either cellular respiration of fermentation Why it matters: Understanding how plants & animals get energy to grow & develop is an important part of biology. Why it matters: Understanding how plants & animals get energy to grow & develop is an important part of biology.