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CHANGING MATTER

Living things use different chemical reactions to get the energy needed for life processes.

CHEMICAL REACTIONS

Changing a substance requires a chemical reaction. During this process, bonds between atoms are broken, and new ones are formed.

A reactant is a substance that is changed in a chemical reaction

A product is a new substance that is formed.

H2 + O2 H20

METABOLISM

Your cells and body get the energy it needs from the food that you eat

Food is digested and broken into small pieces so it can be used by your cells

This requires many complex reactions that release energy in the form of ATP which is your bodies main energy source

ENERGY IN FOOD

Main sources of energy; carbohydrates, fats, and proteins

Calories on food labels give you information as to the energy contained in the food

Metabolizing foods give use energy and heat You can tell how much energy is contained in food

by the heat it produces Can measure this heat by using a calorimeter

CHEMICAL POTENTIAL ENERGY

GLUCOSE

CARBOHYDRATES

ATP is short for adenosine triphosphate. ATP is a:

ATP is the principle source of energy for: all cell activities, processes and chemical

reactions.

***There are other molecules that store energy (glucose and fat) but none is as readily/quickly available as ATP. Ten million ATP molecules are made and remade per minute!

ADENOSINE TRIPHOSPHATE-ATP

nucleotide consisting of adenine, ribose sugar and three phosphate groups.

ADENOSINE TRIPHOSPHATE--ATP

ADENINERIBOSE SUGAR

ADENOSINE

HIGH ENERGY BONDS

PHOSPHATE GROUPS

Notice the last two bonds of ATP are drawn with a squiggly lines to indicate _______________________. High energy bonds

The phosphate groups are negatively charged, thus there is a repelling force between the phosphate groups. This means that

The energy needed to put the phosphates onto the rest of the molecule, comes from the:

it takes a lot of energy to hold the phosphate groups together!

energy from the breakdown of the food you eat.

You can think of ATP as a compressed spring containing a lot of potential energy. If one or two of these phosphates is removed, the spring relaxes and energy is released from the bond.

1. Make macromolecules (carbs, proteins, lipids) by _____________________________ and enzyme action.

Energy from ATP can be used to do work in cells such as:

DEHYDRATION SYNTHESIS

2. Muscle contractions for movement

3. Transport of molecules across a cell membrane (active transport)

ATPACTIVITY

INTRODUCTION Energy within a cell exists in the form of chemical energy. A source of this chemical energy is a com-pound called adenosine triphosphate (ATP). ATP, when changed to a compound called adenosine diphosphate (ADP), releases energy for biological work in a cell. ADP can also be changed back into to ATP, but this reaction requires energy.  

ADP P ATP + H2O

ADP + PATP + H2O

Energy from foodATP synthase

ATPase

+

+

+

+

1. Label the following pictures: ADP, ATP or AMP

H

H

A B C

2. What are the three parts of ATP

3. When Carbohydrates are digested what are theyBroken down into? Carbohydrates → ?

BIOLOGICAL REACTIONS + ENZYMES

In life many of the chemical reactions needed to keep you alive would happen much to slow for us to stay alive

Enzymes are needed so that these reactions can occur very quickly in order to sustain life. Catalase – helps break down toxins in the

body (hydrogen peroxide) Protease – breaks down proteins Lipase – breaks down fats Amylase – breaks down starch

ACTIVATION ENERGY

ENZYMESEnzyme: Is a molecule, usually a protein that

increases the speed of biochemical reactions.

Each enzyme has an active site, the region where the reaction takes place.

The shape of the active site determines which reactants, or substrates, will bind to it. Each different enzyme acts only on specific substrates.

Binding of the substrates causes the enzyme’s shape to change. This change causes some bonds in the substrates to break and new bonds to form.

ENZYMES

Enzymes Many enzymes are proteins. Changes in

temperature and pH can change a protein’s shape.

If an enzyme changes shape, it won’t work well.

Most enzymes need a certain range of temperatures and pH.

COENZYMES

Some enzymes need helpers to carry out their job

They also bind to the active site

COMPETITIVE INHIBITORS

A molecule that is similar to the shape of the enzyme binds to the active site.

The enzyme cannot bind Many poisons and drugs are Competitive inhibitors

ENZYME REVIEW

1.What are the structures labeled A and B

2. What is the purpose of this structure?

3. What two things would affect how the structureWorks?

LAB: CATALASE

THE LIVER Largest organ Weighs 3-3.5 lbs Size of a football Most important organ;

used to produce and store biochemicals

Used to detoxify the body, removes bacteria, stores vitamins

copyright cmassengale

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The liver is located on the right side of your body beneath the ribs.Copyright © 2004 Microsoft Corporation, One Microsoft Way, Redmond, WA 98052-6399 USA. All rights reserved.

DISEASES If the liver is exposed to

toxins for to long it can become damaged and not do it’s job

Cirrhosis – drinking alcohol Hepatitis C Increased salt intake can

decrease the livers ability to break down toxins

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LAB: CATALASE As our bodies remove waste products and

toxins to keep us healthy hydrogen peroxide is produced

H2O2 → H2O + O2

An enzyme (catalase) in our liver breaks down hydrogen peroxide into water and oxygen which is not harmful to us.

When we ingest excess salt the liver cells break down the hydrogen peroxide less effectively.

When we are exposed to extreme conditions our enzymes are affected

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