Chapter 6 Biochemistry

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

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 Bonds Ionic bonds form between ions (ex. salt  NaCl) – Metal + Nonmetal Sodium Chloride – NaCl – Table Salt

Covalent Bonds Covalent bonds form between two nonmetals. (ex. Water  H 2 O – 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 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 Carbohydrates Lipids Proteins Nucleic 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

Glucose Fructose (isomer of glucose) Galactose (isomer of glucose) Ribose Deoxyribose Monosaccharide’s:

Isomers: Same chemical formula but different arrangement of elements: Glucose Galactose

Disaccharides: Sucrose - Table sugar Lactose - Milk sugar Maltose - Malt sugar

Making Disaccharides: Sucrose = glucose + fructose Lactose = glucose + galactose maltose = glucose + glucose

How to build a disaccharide: Done through a process called dehydration synthesis A.k.a. Dehydration reaction Water (H 2 O) is lost

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 digest Long 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. polypeptides Through 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 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 energy Ex. Amylase converts starch to simple sugar

Rates of Chemical Reaction Energy is needed to start reaction: Activation Energy

Reactants Products

What affects enzyme function? pH Temperature

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.)

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 functions  Steroids: Cholesterol, Hormones (testosterone & estrogen)

Function of Lipids (cont.) 3. Provide structure: in cells & waxy coating on plants

Saturated Fats Called triglyceride Hard & solid at room temp Ex. Meat, Dairy, Butter, Chocolate, Animal Fats

Unsaturated Fats “Kinked” carbon chain Liquids at room temp Ex. Peanuts, Fish, Olive Oil

Saturated v.s. Unsaturated

Trans Fats Worst type of fat Increases 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 = Nucleotide Two types DNA & RNA

DNA Deoxyribonucleic acid Store genetic information Double helix

RNA Ribonucleic Acid Helps synthesize (create) proteins