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ATP and Chemical Energy

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Objectives

• SWBAT recognize the importance of ATP as an energy-carrying molecule.

• SWBAT identify energy sources used by organisms.

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Review Vocabulary

• Glucose• Carbohydrate• Monosaccharide• Polysaccharide• Starch• Cellulose

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What is this molecule?

• What is this molecule?– C6H12O6

• Who makes it?

• Why is it important?

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Glucose is the building block

• Glucose is linked together to make all sorts of different macromolecules (molecules that are really big) like starch and cellulose.

These are 2 glucose molecules joined to

make a molecule known as table sugar

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Vocabulary

• ATP• ADP• Homeostasis• Triglyceride• GlucoseReview Vocabulary If Needed• Carbohydrate• Monosaccharide• Polysaccharide• Starch• Cellulose

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SciShow: ATP and Cellular Respiration

• https://www.youtube.com/watch?v=00jbG_cfGuQ

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Energy and Food

• When we need energy, we eat.– The foods we eat are carbon-based molecules –

carbohydrates, starches, proteins, lipids, etc.• The question then is, how does food give you

energy?

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Energy and Food• Before energy can be extracted from food, it

has to be broken down (energy comes food but not directly). There is no ATP in the food you eat.

• All the carbon-based molecules in food contain energy in their bonds.– This energy is useable only when those bonds are

broken and the energy is released. – Carbohydrates and lipids are the most important

energy sources in the food you eat.

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Bonds need to be broken

Starch molecule

Glucose molecule

• Molecules in food store chemical energy in their bonds – breaking the bonds frees energy.

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ATP - Currency of Cellular Energy

phosphate removed

• ATP transfers energy from the breakdown of food molecules to cell functions.– Energy is released when a phosphate group is removed.

– ADP is changed into ATP when a phosphate group is added.

Energy from breaking the carbon and other bonds in

the food you eat.Energy is released when a

phosphate is removed from the ATP molecule.

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ATP - Currency of Cellular Energy

• ATP is chemical energy that is available to the cell to power its necessary functions. – Your cells use ATP to move materials by active

transport, exocytosis, and endocytosis.– They also use ATP to create molecules such as

proteins, lipids, nucleic acids, and any other molecule they need in order to function properly (to maintain homeostasis).

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ATP - Currency of Cellular Energy

Biosynthesis is the production

of complex molecules

within living cells.

Energy is released when a phosphate is removed from the

ATP molecule.

When the phosphate is removed and energy released,

ATP becomes ADP.

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ADP

• ADP is adenosine diphosphate. – It is a lower-energy molecule than ATP. – It can be converted into ATP by the addition of a

phosphate group.

phosphate removedThis is a simplified version of the cycle that turns ADP into ATP. This process is not simple.

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ATP/ADP

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Molecular Structure of ATP

Nucleoside

Ribose

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Making ATP• Digestion breaks down food into smaller

molecules (think glucose) that then can be used to make ATP.– Different foods have different amounts of calories,

which indirectly related with how much ATP each type of food can make.

– Carbohydrates are the most commonly broken down molecule to make ATP. The breakdown of the simple sugar glucose yields about 38 molecules of ATP.

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Making ATP

• The body does not store carbohydrates (it burns them); however, the body does store lipids.– Lipids store about 80% of the energy in your body

– they are our fat stores. – When broken down, they make about 146

molecules of ATP from one triglyceride (this is why animals pack on the fat to survive periods when there is very little food).

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Making ATP• Proteins are least likely to be broken down to make ATP.

– amino acids not usually needed for energy– about the same amount of energy as a carbohydrate

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Making ATP

This is a wild polar bear who lives on Hudson Bay (in Manitoba). While waiting for the ice to form, this polar bear made a friend – a sled dog. The bear visited the dog on several occasions to play. When the ice formed, the bear went on his way.

Polar bears will go months without eating (stranded on land) – living on their fat until pack ice is formed and they can hunt seals.