Chapter 3

Cell Processes

Section 1:

I. Chemistry of Life

A. Nature of Matter

1. Matter: anything that has mass and

takes up space.

2. Energy: anything that brings about

change.

a. Energy can hold things together or break

things apart.

I. Chemistry of Life

B. Atoms

1. Matter is made up of atoms

a. Atoms are the smallest unit of anything.

2. The center of an atom is called the

nucleus.

a. The nucleus contains two atomic particles

called protons and neutrons.

I. Chemistry of Life

3. Atoms are made up of three smaller

particles.

a. Protons: positive charge; found in nucleus.

b. Neutrons: neutral charge; found in nucleus.

c. Electrons: negative charge; found in electron

cloud.

ATOMIC MODEL

I. Chemistry of Life

4. The charge of the nucleus of

an atom is positive because it

has only protons (+) and

neutrons (0).

I. Chemistry of Life

5. Electrons are important because they

are the parts that are involved with all

chemical reactions.

6. Electrons are the smallest particle in an

atom.

7. Atoms are usually neutral (they do not

have a charge).

a. This is because the protons in an atom usually

equals the electrons.

Noah and Noah working on

their virus paper!!!!

I. Chemistry of Life

C. What is an Element

1. An element is matter that is made up of

only one kind of atom.

2. Cannot be broken down into simpler

forms.

3. Each element is given a 1, 2, or 3 letter

symbol.

a. Some symbols are from Latin names.

b. Some symbols are from common names.

c. Examples given in class!!!! Pay attention

I. Chemistry of Life

4. There are currently 118 Elements.

a. 90 are natural elements, 28 are man made

elements.

D. The Periodic Table of Elements

1. A list of all elements by size (atomic

number), the smallest are in the upper

left (Hydrogen), the heaviest are at the

bottom right (#118)

2. The table shows the name, symbol, and

how many protons it has.

PERIODIC TABLE

I. Chemistry of Life

E. Elements of Life1. 99% of all living matter is made up of six

elements.

2. Humansa. O-oxygen=65%

b. C-Carbon= 18.5 %

c. H-Hydrogen = 9.5%

d. N-Nitrogen = 3.2%

e. Ca-Calcium = 1.5%

f. P-Phosphorus = 0.4%

g. See entire chart on page 67 of your textbook

I. Chemistry of Life

F. What is a Compound?1. A compound is a substance made up of 2 or

more elements combined chemically in exact proportions.

2. EX: WATER is always 2 H to 1 O or H2O.

3. Compounds act and appear differently than the original elements.

a. Hydrogen is explosive, and a poisonous gas.

b. Oxygen is a gas needed for combustion in its elemental form.

c. When they combine they make vital liquid water.

I. Chemistry of Life

G. Molecules (type of compound #1)

1. Molecules: Group of atoms held together by energy of chemical bonds.

a. Formed when different atoms share their

outermost electrons.

b. Sharing of electrons is called COVALENT

BONDING.

c. Water is an example of a molecule because

the 2 hydrogen share electrons with 1 oxygen.

I. Chemistry of Life

H. Ions (Type of Compound #2)

1. Compounds that form when atoms of opposite charges called ions connect.

a. Ions are atoms with a positive or a negative charge.

2. Anion

a. When an atoms has more electrons than protons

giving the atom an overall negative charge.

3. Cation

a. If the atom has more protons than electrons; the

atom now has a positive charge.

I. Chemistry of Life

4. Ions of opposite charges attract one

another and form IONIC COMPOUNDS.

5. Example: Na+ + Cl- = NaCl (Table Salt)

6. Ions are very important inside the human

body.

I. Chemistry of Life

I. Mixtures

1. When two substances join together but

keep their own properties.

a. This is different than a compound!!!

b. Examples: Blue and Red Marbles in a

bag, Small rocks in river water, Iced Tea, etc.

c. Mixtures can be separated by physical means!!

d. We will discuss in class why compounds and

mixtures are different!!! PAY ATTENTION!!

I. Chemistry of Life

J. Solutions (Type of Mixture)

1. A solution is a special type of mixture.

2. A solution is when two or more substances

are mixed together EVENLY.

a. One substance is dissolved in another

substance.

b. Examples: Soda, Iced Tea, etc.

c. A solution can be separated by physical

means.

I. Chemistry of Life

K. Suspensions (Type of Mixture)

1. When two or more substances are mixed

together but will eventually settle out over

time.

a. Example: Italian Salad Dressing will separate

into oil and vinegar over time.

b. Suspensions are different than solutions

because solutions should not settle out over

time!!!

I. Chemistry of Life

L. Food Pyramid

1. A chart explaining the types of foods and

the amounts a person should have on a

daily basis.

2. A balanced diet consists of several types

of ORGANIC COMPOUNDS.

I. Chemistry of Life

M.Organic Compounds

1. Substance that contains Carbon and

Hydrogen and are associated with living

things.

2. Exceptions: Things that are non-living but

were made from once living things.

a. Example: Coal is made from dead and

decaying plant materials.

I. Chemistry of Life

3. There are four kinds of organic

compounds.

a. Carbohydrates

b. Lipids (Fats)

c. Proteins

d. Nucleic Acids

I. Chemistry of Life

N. Carbohydrates

1. Made up of sugars and starches.

2. Job/Function: to supply energy for cell processes. a. The main energy source for the cell.

3. Examples: Potatoes, vegetables, fruits, breads, rice, and pasta.

4. Food Pyramid: most important part of diet in terms of quantity. (Eat more carbs than any other food group).

5. If a person or cell is active the carbohydrates you eat will be completely burned up during the course of the day.

Carbohydrates

I. Chemistry of Life

O. Lipids1. Function/Job: An energy backup for cells.

2. If not used they are stored as a fat called cellulite.

a. Once stored it is very hard for the body to lose.

3. Fats and Oils are examples of lipids.

4. Foods rich in lipids: Mayo, Salad Dressing, Ice Cream, Dairy products, Chocolate, Oil, Butter, Etc.

5. A human only needs a very small amount of lipids per day.

Lipids

I. Chemistry of Life

P. Proteins

1. Function: Responsible for all chemical

reactions that occur inside the human

body!!

2. Made up of amino acids (20 common

amino acids)

I. Chemistry of Life

3. Special kinds of proteins called ENZYMES

regulate the rate of chemical reactions.

a. Example: Saliva helps break down

carbohydrates in the mouth faster.

b. Lactase helps break down mild products.

4. Foods rich in proteins:

Meats, fruits, veggies, fish, eggs, peanut

butter, nuts.

5. Vegetarians NEED to be careful to make

sure they get enough protein in their diet!!

Proteins

I. Chemistry of Life

Q. Nucleic Acids1. Function: Responsible for all genetic

information in cells.

2. Two Types of Nucleic Acidsa. DNA (Deoxyribonucleic Acid): Carries all the

genetic information for the cell. FOUND IN THE NUCLEUS!!

b. RNA (Ribonucleic Acid): Carries the DNA (plan) to all cell parts; also makes proteins and enzymes.

3. Nucleic Acids are the most complex of all organic compounds!!!

DNA

I. Chemistry of Life

R. Inorganic Compounds1. Made from other elements besides water.

2. Normally they are simpler than organic compounds.

3. See chart page 71 to see the important inorganic compounds in the human body.

4. WATER is the most important INORGANIC compound for living things!!

5. Life is composed of at least 50% water.

6. Human cells are made of at least 70% water.

I. Chemistry of Life

S. Importance of Water1. Animals can live for only days without water

but weeks without food!

2. Every chemical reaction in the body needs to be in a water-like solution.

a. Example: Blood

3. Water is composed of 2 hydrogen atoms and 1 oxygen atom. a. Because of this water has a positive and negative

side!!

b. Don’t worry…we will discuss this in 8th grade!!!

Water: The Mickey Mouse

Molecule!!!