6.2 Chemical Reactions

I. Reactants and Products A. Chemical equations a. Reactants and Products What are ways that arrows can be read in a chemical equation?

"yields" or "react to form" Reactants —

III. Enzymes Enzymes affect MANY BIOLOGICAL PROCESSES. Give examples.

1. Person bit y snake -enzymes in the venom break down the membranes if that's persons red blood cells 2. Hard green apples ripen -due to the action of enzymes( ENZYMATIC BROWNING) 6.2- when sliced, an Apple's soft tissues is exposed to oxygen causing a chemical reaction (oxidation)z enzymes in the apple speed this reaction, producing darkened colored fruit, 3. PHOTOSYNTHESIS/CELLULAR RESPIRATION - provide energy for the cell with the help of enzymes

Understand Figure 6.18 to learn how an enzyme works

1. Substrates interact with enzymes at specific places called ACTIVE SITES REMEMBER!! Only substrates with a specific shape can bind to the active active site of an enzyme 2. Once the substrates bind to the active site, the active site hanged and forms the ENZYME - SUBSTRATE COMPLEX 3. the substrates react to form PRODUCTS 4. The enzyme then RELEASE the product

I. Reactants and Products How do you know when a chemical reaction has taken place? You can know when chemical reaction is taking place ...

1. Surface/ appearance 2. Production of heat or light 3. Formation of gas, liquid, or solid However, you may not know all the reactions taken inside your body just by these evidences

I. Reactants and Products Example of Physical change

1. Water- ice melting, water boiling, liquid water to ice Only the appearance of water has been altered 2. Crumpling up paper

III. Enzymes Enzymes in the human body work and it's OPTIMUM BEST EFFICIENCY when the body is at what temperature

27C (98.6F) (Normal body temperature)

III. Enzymes Although a catalyst is important in speeding up a chemical reaction, what does it NOT do

A catalyst DOES NOT increase how much product is made Also it DIES NOT get used up in the reaction

I. Reactants and Products After a chemical change, such as rusting, what is formed?

A new substance is formed after a chemical change

Process

A series of steps or actions that produce and end product

III. Enzymes What is a catalyst?

A substance that speeds up a chemical reaction by lowering and reducing the activation energy needed to start a chemical reaction Thereby enabling the reaction to proceed much more quickly They are the substances that ALTER chemical reactions

III. Enzymes To be useful to living organisms what has to be done to chemical reaction's to reduce the activation energy and allow the reaction to proceed quickly

Addition substance must be present

I. Reactants and Products What is Physical change?

Alters the substance's appearance* but NOT is composition Overall composition DOES NOT change

III. Enzymes What clue about the enzyme can you tell just by look at an enzymes NAME?

An enzyme's name describes what it does Example: Amylase

III. Enzymes Why do the chemical reactions in living things proceed very slowly when carried out in the laboratory?

Because he activation energy is high

II. Energy of Reaction B. Energy change in chemical reactions What do both exothermic and endothermic reactions have in common?

Both require activation energy to get started Exo- reactants > Products Endo- reactants < Products

III. Enzymes Chemical reactions inside the human body would proceed far too slowly to be useful if it were not for the action of

Catalyst

Figure 6.17 Compare the activation energy of the reaction without enzyme to the activation energy of the reaction with enzyme

Catalysts lower the activation energy for reactions. The lower the activation energy for a reaction, the faster the rate. Thus enzymes speed up reactions by lowering activation energy. Many enzymes change shape when substrates bind.

I. Reactants and Products A. Chemical equations a. Reactants and Products Give an example of a chemical equation to describe the reaction that provides energy

Cellular respiration formula C6H12O6 + O2 —

I. Reactants and Products During* chemical reactions, what is happening?

Chemical BONDS are broken/and or formed

I. Reactants and Products A. Chemical equations What is a shorthand way scientist express each components of the reactions? In other words, what is a simple way to write chemical reactions?

Chemical equations

I. Reactants and Products A. Chemical equations In a chemical equation, it has formulas and arrows. Chemical formulas describe.... Arrows indicate...

Chemical formulas describe the substances in the reaction Arrows indicate the process of change

Main idea of 6.1

Chemical reactants allow livjng things to grow, develop, reproduce, and adapt

I. Reactants and Products A new car and its shining chrome and clean appearance is appealing. Over time, the cafe might get rusty and lose. This rust is a result of a chemical change called.....

Chemical reaction

II. Energy of Reaction A. Activation Energy Endothermic reaction is

Chemical reaction in which heat is absorbed; Energy of the product is higher than that of the reactants Opposite of exothermic More energy in products than reactants as the reaction progress

III. Enzymes Just as worker bees are important for the survival of a beehive, enzymes are the ________________ in a cell

Chemical workers

I. Reactants and Products A. Chemical equations b. balanced equation What can you use to make the number of atoms in each side of the arrow equal;

Coefficients; The number written in front of a reactant or a product; you can change to balance Large numbers in front of chemical formulas

III. Enzymes The active site and the substrate have _______________ shapes. What does this enable?

Complementary shapes The enables them to interact g in a precise manner, similar to a puzzle piece fitting tkbeghef

Explain why chemical equations must be balanced

Conservation of mass/matter Matter cannot be created of destroyed so all chemical equations must show this balance of mass. Therefore the number of atoms of each element on the reach side must equal the number of atoms of the same element on the product side.

III. Enzymes Amylase is an important enzyme found in saliva*. What is it's role?

Digestion of the food begins in your mouth when amylase speeds the breakdown of amylose, one of the two components of start he.

III. Enzymes Like al catalyst, enzymes do not ....

Do get used up by the chemical reaction Once it has participated in a chemical reaction, it can be used again

An ice pack is an example of an ________________ reaction why.

Endothermic; This reaction absorbs heat from the surroundings, quickly lowering the pack's temperature.

II. Energy of Reaction Connection to Physics The key to starting a chemical reaction is

Energy Just like how a cookie with all the ingredients mixed are not a cookie until you bake it. Something must start the change from cookie dough to cookie. Energy in the form of HEAT is needed

Be able to know and label parts of Graph. Draw it

Energy diagrams of exothermic and endothermic. Know why it is. Energy diagram of with and without enzymes Diagram of substrate binding with enzymes to make a product

Watch interactive figure on "biologygmh.com"

Enzyme activity video

Summarize the importance of enzymes in living things

Enzymes are needed for metabolic pathways in the body, respiration, digestion and other important life processes. When enzymes function properly, homeostasis is maintained.

III. Enzymes What are enzymes?

Enzymes are special proteins that are biological catalyst that speeds up the rate of chemical reactions in biological processes by lowering the activation energy needed to start a reaction

Lighting a match onto a candle wick is an example of _______________reaction

Exothermic the reaction of burning the candle is exothermic because more energy is given off when the candle burns than is put in to light it.

KNOW THE TWO ACTIVATION ENERGY DIAGRAMS

FUGHRE 6.15-6.16

True/ False All compounds in living can* undergo chemical reactions without energy

False, Most compounds in living things can undergo chemical reactions without energy

True or False/ When you sleep, your body is completely at rest.

False; chemical reactions are constantly happening within our body Body still digesting food Scrape on elbow is healing Muscles and bones will be growing and developing

True/False: Substance can only undergo changes only through chemical reactions

False; substances can undergo changes that do NOT involve chemical reactions Ex: Physical changes

Summarize the relation ship between an enzyme and a substrate

Fit together like a puzzle 1 substrate that each enzyme will bind together

Figure 6.15

For the reactants X and Y to form product XYenergy is required to stay the reaction The peak in the graph represents the amount of energy that must be added to the system to make the reaction go However, some reactions DO NOT happen because they have a VERY HIGH activation energy

III. Enzymes What does enzyme substrate complex help with? Figure 6.18

Helps chemical bonds in the reactants to be broken and new bonds to form

Diagram the energy changes that can take place in a chemical reaction. Relate* energy changes to chemical reactions

In an exothermic reaction, the products are at a lower energy than the reactants. In an endothermic reaction, the products are at a higher energy than the reactants.

I. Reactants and Products Rust on a chain creates a compounds called

Iron oxide (Fe2O3g

I. Reactants and Products Examples of chemical reaction

Iron rusting Wood burning

II. Energy of Reaction B. Energy change in chemical reactions In ever chemical reaction, there is a change in energy. Why?

It is because and she to the making* and breaking* of chemical bonds as reactants for Products

I. Reactants and Products A. Chemical equations b. balanced equation Antoine Lavoisier law says matter cannot be created or destroyed. Which law is this?

Law of Conservation of Matter

I. Reactants and Products A. Chemical equations b. balanced equation what is the first methods on how you can balance an equation?

Method 1: Multiply the coefficient by the subscript for each event

III. Enzymes Most enzymes (like amylase) are specific to __________ reaction

One reaction Works like a lock n key or puzzle piece system

II. Energy of Reaction B. Energy change in chemical reactions What is evidence that chemical reactions are happening inside our bodies?

Our body temperature of about 37C/ 98.2Ft

I. Reactants and Products Give an example of how chemical bonds are broken and or formed during chemical reactions.

Rust on a chain (iron oxide) Formed when Oxygen (O2) in the air reacted with iron (Fe)

Identify which number indicates the number of atoms of each element in a molecule of a substance

Subscribts

I. Reactants and Products A. Chemical equations What are the products?

Substance formed* after * by a chemical reaction starts Located on the left side of the arrow in a chemical equation

I. Reactants and Products A. Chemical equations a. Reactants and products A chemical equation consists of reactants and products. What are the reactants?

Substance that exists before* a chemical reaction starts Located on the left side of the arrow in a chemical equation

I. Reactants and Products A. Chemical equations b. balanced equation What does is mean when chemical equations must* show a balance of mass?

The # of atoms of the same element on the reactant side must equal the number of atoms of the same element on the product side

II. Energy of Reaction A. Activation energy Exothermic chemical reaction is

The chemical reaction in which heat is produced "Exit"- releases energy as heat; heat out; energy given off; MORE energy in the Reactant than Product as the reaction progress

II. Energy of Reaction A. Activation Energy Give an example of activation energy. Starting with a Flame in a wick.

The flame of the match provides activation key (the amount of energy needed to begin a reaction) This reaction gives off energy in the form of heat and light. The flame also provide she energy for the reaction of the substances in the candle wick with oxygen AFTER the reaction, no further input of energy is needed and the candle continues to burn on its own

II. Energy of Reaction A. Activation energy What is the activation energy?

The minimum amount of energy needed for reactants to form products in a chemical reaction

I. Reactants and Products Chemical reaction is

The process by which ATOMS or groups in substances are reorganized into DIFFERENT substances Changes its original composition

III. Enzymes What are substrates?

The reactants that bind to the enzyme

III. Enzymes What are the active sites?

The specific location where a substrate binds in an enzyme

I. Reactants and Products A. Chemical equations b. balanced equation The law of conservation of matter must hold TRUE in chemical reactions. Why?

They all must show this balance. In chemical reactions, matter cannot be created or destroyed.

III. Enzymes True or false: scientists use many types of catalysts to make reactions go thousands of times faster than the reaction would be able to go without the catalyst

True

True/ False A catalyst have a specific enzyme to bind with

True

True/ False Balanced chemical equations must show an equal number of atoms of each element on both sides

True

True/ False if you change the substrate you'd have to change the enzyme

True

I. Reactants and Products (placed wrong) A. Chemical equations b. balanced equation Easy method of balancing an equation

Use LOWEST COMMON MULTIPLE 1. Create a table: split it in half between the arrow 2. Write the types of elements on both sides 3. Write the number by multiplying coefficient as subscribe 4. If you see that they are not equal on all columns. Then you have to change 5. Start fixing Metal. Start fixing Nonmetals expect Oxygen and Hydrogen. Then finally fix Oxygen and Hydrogen if needed.

Figure 6.17 Reaction progress with and without enzymes Compare the progress of the reaction to see the effect of an enzyme in a chemical reaction

When an enzyme acts as a biological catalyst, the reaction occurs at a rate that is USEFUL to cells

III. Enzymes Enzymes are _________[ to life

essential

III. Enzymes All living things are chemical _____________ driven by chemical ______________

factories reactions

Why can you only change coefficients not subscripts?

oefficients in a chemical equation indicate how many molecules of each type take part in the reaction. Subscripts are part of the chemical formula for reactants or products and cannot be changed to balance an equation

III. Enzymes What factors can affect an enzymes activity? Give an example

pH temp For Ex, most enzymes in human cells are most active at an optimal temp close to 37C. However, enzymes in other organism such as bacteria can be active at other temps

I. Reactants and Products A. Chemical equations b. balanced equation What are subscripts* in a chemical equation?

smaller numbers at the right corner of the element; YOU CAN NEVER CHANGE THESE TO MAKE AN EQUATION EQUAL

Difference between coefficients and subscripts

the coefficients give the number of molecules (or atoms) involved in the reaction Subscripts are part of the chemical formula for reactants or products and cannot be changed to balance an equation