Download ppt - Energy for Life Chapter 4 Section 3 p. 113- 117. A. Cells use Chemical Reactions Cells use chemical reactions to change the chemical energy stored in

Energy for LifeEnergy for Life

Chapter 4 Section 3Chapter 4 Section 3

p. 113- 117p. 113- 117

A. Cells use Chemical Reactions A. Cells use Chemical Reactions

Cells use chemical Cells use chemical reactions to change reactions to change the chemical the chemical energyenergy stored in food into stored in food into forms needed to forms needed to perform cell perform cell activitiesactivities


1. 1. Metabolism –Metabolism – The The total of all total of all

chemical reactionschemical reactions

in an organismin an organism


2. Chemical reactions 2. Chemical reactions require require enzymes enzymes

(which cause, or (which cause, or speed up, or slow down speed up, or slow down

reactions without reactions without themselves being themselves being changed and therefore changed and therefore can be used again and can be used again and again.) again.)

B. PhotosynthesisB. Photosynthesis

The process that plants The process that plants and other organisms use and other organisms use to convert sunlight to convert sunlight energy into chemical energy into chemical energy or sugars energy or sugars (glucose) to be used as (glucose) to be used as food.food.


1. 1. Producers Producers – organisms that make their own – organisms that make their own foodfood

Consumers Consumers – organisms that can not make – organisms that can not make their own food.their own food.


Chlorophyll and Chlorophyll and other pigments are other pigments are used in used in photosynthesis to photosynthesis to capture capture sunlightsunlight

Which is used to Which is used to produce sugar produce sugar (glucose) and (glucose) and oxygen oxygen

C. RespirationC. Respiration

The process in which chemical reactions break The process in which chemical reactions break down food molecules into simpler substances down food molecules into simpler substances and and release stored energyrelease stored energy


1. Respiration of carbohydrates begins in the 1. Respiration of carbohydrates begins in the cytoplasmcytoplasm



a. Carbohydrates are broken down into a. Carbohydrates are broken down into glucose glucose moleculesmolecules



a. Carbohydrates are broken down into a. Carbohydrates are broken down into glucose glucose moleculesmolecules

b. Each glucose molecule is broken down into b. Each glucose molecule is broken down into two simpler molecules, releasing energy.two simpler molecules, releasing energy.

+ +

2. Respiration moves into the 2. Respiration moves into the mitochondriamitochondria


2. Respiration moves into the 2. Respiration moves into the mitochondriamitochondria a. The two simpler molecules are a. The two simpler molecules are broken downbroken down

again, releasing much more energy.again, releasing much more energy.


+

2. Respiration moves into the 2. Respiration moves into the mitochondriamitochondria a. The two simpler molecules are a. The two simpler molecules are broken downbroken down

again, releasing much more energy.again, releasing much more energy. b. This process uses oxygen and produces b. This process uses oxygen and produces

carbon dioxide (COcarbon dioxide (CO22) and water as waste ) and water as waste products.products.


C6H12O6 + 6O2 6CO2 + 6H2O + energy

glucose oxygen carbon water

dioxide

D. FermentationD. Fermentation

Cells that do not have enough oxygen for Cells that do not have enough oxygen for respiration use this process to release respiration use this process to release somesome of of the energy stored in the energy stored in glucoseglucose molecules molecules



1. Entire process occurs in the 1. Entire process occurs in the cytoplasmcytoplasm..



1. Entire process occurs in the 1. Entire process occurs in the cytoplasmcytoplasm.. 2. Produces 2. Produces lactic acidlactic acid, , alcoholalcohol, and carbon , and carbon

dioxide as wastesdioxide as wastes

E. ComparisonsE. Comparisons

Photosynthesis and respiration are almost the Photosynthesis and respiration are almost the opposite of each other.opposite of each other.

E. ComparisonsE. Comparisons

Photosynthesis and respiration are almost the Photosynthesis and respiration are almost the opposite of each other.opposite of each other.

1. Photosynthesis produces (end products are) 1. Photosynthesis produces (end products are) glucose and oxygenglucose and oxygen which are used in which are used in respirationrespiration

6CO2 + 6H2O + energy C6H12O6 + 6O2

carbon water sunlight glucose oxygen

dioxide energy

E. ComparisonsE. Comparisons Photosynthesis and respiration are almost the Photosynthesis and respiration are almost the

opposite of each other.opposite of each other. 1. Photosynthesis produces (end products are) 1. Photosynthesis produces (end products are)

glucose and oxygenglucose and oxygen which are used in respiration which are used in respiration 2. Respiration produces (end products are) 2. Respiration produces (end products are) carbon carbon

dioxide and waterdioxide and water, which are used in , which are used in photosynthesisphotosynthesis

C6H12O6 + 6O2 6CO2 + 6H2O + energy

glucose oxygen carbon water chemical

dioxide energy

6CO2 + 6H2O + energy C6H12O6 + 6O2

carbon water sunlight glucose oxygen

dioxide energy