Chapter 6Biochemistry

Basic Chemistry

Living things are made up of matter & all matter is composed of atoms

Composition of Matter

Matter is anything that has mass and takes up space

All organisms are composed of matter

Composition of Matter

Elements are made of atoms

Elements bond to make compounds

Atom

An atom is the basic unit of matter.

They are composed of subatomic particles

– Protons (+)– Neutons (0)– Electrons (-)

Atoms

Horizontal rows are called periods. Vertical columns are called groups.

Hydrogen (element name)

Atomic Number (equal to the # of protons or # of electrons)

Element Symbol Atomic Mass (equal to

the number of protons, neutrons & electrons in a single atom)

Hydrogen

1

1.008

Ions

An ions is an atom that has gained or lost electrons.

Anions gain electrons – (ex. Cl-)

Cations lose electrons– (ex. Na+)

Chemical Bonds

Force that holds two or more ions or atoms together– Single, double, or

triple bonds

Bond

Ionic BondsIonic bonds form between

ions (ex. salt NaCl)– Metal + Nonmetal

Sodium Chloride – NaCl – Table Salt

Covalent Bonds

Covalent bonds form between two nonmetals.(ex. Water H2O–Nonmetal + Nonmetal–Forms when electrons

are shared

van der Waals Forces

Attractive forces between oppositely charged regions of molecules.

Geckos Climbing Glass Surface:

Attributed to Van der Waal forces

Between surface and microscopic projections on their feet!

Molecules of Life

You Are You Are What What You EatYou Eat

““You Are What You Eat”You Are What You Eat”

Nutrition Facts label–a summary of our basic biochemistry

–Why do we need to eat these?

Organic Molecules Contain carbon Molecules join to form

Macromolecules: large molecules

Held together with covalent bonds

Macromolecules are Polymers

Polymers are molecules held together by covalent bonds

Made of monomers

Four classes of macromolecules

CarbohydratesLipids ProteinsNucleic Acids

Carbohydrates Provide energy to cells Subunit = glucose Contain carbon, hydrogen and oxygen.

Types of Carbohydrates

1. Simple carbohydrates mono- & di-saccharides

2. Complex carbohydrates Starch, glycogen, and

cellulose Known as polysaccharides

Simple Carbohydrates

Easy to digest Monosaccharide Examples:

–Glucose: simple sugar–Fructose: fruit sugar–Lactose: milk sugar

GlucoseFructose (isomer of glucose)

Galactose (isomer of glucose) RiboseDeoxyribose

Monosaccharide’s:

Isomers: Same chemical formula but

different arrangement of elements:

GlucoseGalactose

Disaccharides:

Sucrose - Table sugarLactose - Milk sugarMaltose - Malt sugar

Making Disaccharides:

Sucrose = glucose + fructoseLactose = glucose +

galactose maltose = glucose + glucose

How to build a disaccharide:

Done through a process called dehydration synthesis

A.k.a. Dehydration reaction

Water (H2O) is lost

http://nhscience.lonestar.edu/biol/dehydrat/dehydrat.html

How to break down a disaccharide:

You break down a disaccharide or a polysaccharide by Hydrolysis

Water (H2O) is added!Disaccharides must be broken

down or digested before entering the cell.

Complex Carbohydrates

Longer to digestLong chains of

monosaccharides so they are

polysaccharides

Complex Carbohydrates (cont.)

Starch Glycogen: energy storage Cellulose: plant

structure

Starch:

Long repeating chains of monosaccharides.

It is called cellulosewhen found in plant tissue (roots and grain)

It is called glycogen when found in animal tissues (muscles and liver)

Glycogen:

Used for energy storage so when the body needs energy between meals or during physical activity it is broken down into glucose.

Cellulose:

Provides structural support in plant cell walls.

Becomes fiber when we eat plants; helps regulate us!

Discussion Questions:

1. Why should we limit some simple sugars?

2. Why do athletes eat complex carbohydrates before a long run / game?

Proteins

Subunits = amino acids Amino acids are made up

of C, H, N, O, and sometimes sulfur.

There are 20 amino acids!

Proteins

Several covalent bonds called peptide bonds join amino acids together to form proteins.

Proteins a.k.a. polypeptidesThrough what process? How do you

build a polymer?

Proteins

Proteins differ in:–#, type & the arrangement of amino acids

Proteins

Make up 15% of your total body mass

Affected by the order of the amino acid chain.

Typically made up of 100 + amino acids.

Protein Function:

Chains combine to form proteins or polypeptides!

Protein Function:

What do proteins do?

1. Enzymes: speed up or Increase rate of chemical reactions / lowers activation energyEx. Amylase converts

starch to simple sugar

Rates of Chemical Reaction

Energy is needed to start reaction: Activation Energy

Reactants

Products

What affects enzyme function?

pHTemperature

What do proteins do? (cont.)

2. Transport: substances inside the cell and between cells

Ex. Hemoglobin (red blood cell protein- carries Oxygen)

3. Defense: Antibodies which are used to defend the body from foreign invaders.

What do proteins do? (cont.)

4. Structure: Collagen, Ligaments,

Tendons are made

up of proteins.

What do proteins do? (cont.)

5. Regulation: can be

Hormones

Ex. Insulin which regulates

glucose levels in the body!

What do proteins do? (cont.)

What do proteins do? (cont.)

6. Motion: muscle protein which allows you to move!

Lipids

Subunit = Fatty Acids Insoluble in water but

soluble in oil Important for

homeostasis

Function of Lipids

1.Energy storage (Fat)

2.Regulate body functionsSteroids: Cholesterol,

Hormones (testosterone & estrogen)

Function of Lipids (cont.)

3. Provide structure: in cells & waxy coating on plants

Saturated Fats

Called triglycerideHard & solid at room temp

Ex. Meat, Dairy, Butter, Chocolate, Animal Fats

Unsaturated Fats

“Kinked” carbon chainLiquids at room temp

Ex. Peanuts, Fish, Olive Oil

Saturated v.s. Unsaturated

Trans Fats

Worst type of fatIncreases risk of

heart problems

Discussion Questions

Which type of fats should we eat less of?–Saturated & trans fats: linked to heart disease

Discussion Questions

How many calories must you burn to lose 1 lb of fat?–3,500 calories!!!

Nucleic Acids

Subunit =

NucleotideTwo types

DNA & RNA

DNA

Deoxyribonucleic acidStore genetic

informationDouble helix

RNA

Ribonucleic AcidHelps synthesize

(create) proteins