Biochemistry

Biochemistry

No Carbon

Inorganic

Non-Living Things

Small MoleculesW

ater

Sal

ts

Aci

ds

Bas

es

Low Energy

Biochemistry

Has Carbon

Organic

Living Things

Large MoleculesC

arb

oh

ydra

tes

Lip

ids

Pro

tein

s

Nu

clei

c A

cid

s

High Energy

• Do not contain Carbon (carbon dioxide is an exception)

• Not made or created by living things

• Typically small ionically bonded molecules

• Examples: Water, Salts, Acids, Bases

Inorganic CompoundsInorganic Compounds

Organic CompoundsOrganic Compounds

• Contain Carbon as primary “backbone element”

• Are molecules that are made from and was once part of living things

• Typically called “macromolecules” due to their large size and number of atoms

• Mostly covalently bonded molecules (great deal of stored energy in their bonds)

• Examples: Carbohydrates, Lipids, Proteins, Nucleic Acids

Inorganic Molecules

• Water• Salts• Acids• Bases

1. Water recall….

• Polarity

• Hydrogen bonds

• Transparent

• Universal Solvent

• Cohesion

• Surface Tension

• Adhesion

• Capillary action

• Albedo Effect• Relative Humidity

• Water Cycle

• Density

• Boiling Point, Freezing Point

• Specific Heat, Latent Heat

• High Heat Capacity

2. Salts, Minerals, Electrolytes

• Important ionically bonded compounds found in living things needed for nerve impulses, muscle contraction, and general cellular functioning

• Most body fluids contain “salt” solutions.

• According to many biologists, this is due to life evolving in the ocean

3. Acids

• Acids are ionic substances that dissociate in water to produce hydrogen ions and some other negative ion

Dissociate = split into ions when placed in water

HCl H+ + Cl-

Hydrogen Ion

Characteristics of Acids …

• Corrosive

• Taste Sour

• Citric fruits (Citric Acid)

• Hydrochloric Acid = HCl

• Sulfuric Acid = H2SO4

• Acetic Acid = Vinegar

Examples of Acids …

4. Bases

• Bases are ionic substances that dissociate in water to produce hydroxide ions and some other positive ion.

NaOH Na+ + OH-

Hydroxide Ion

Characteristics of Bases…

• Feel Slippery

• Taste Bitter

Examples of Bases…• Cleaning Products

• Bleach

• NaOH = Sodium Hydroxide

• Baking Soda

Acid/Base Solutions

• Acidity or alkalinity (base) is a measure of the relative amount of H+ and OH- ions dissolved in a solution. Neutral Solutions have an equal number of H+ and OH- ions.

The pH Scale compares the relative concentration of H+ ions and OH- ions

Each pH unit is 10X stronger or weaker !

Litmus Paper• Simple paper test to determine if a substance is acidic or basic

Acid Base Neutralred stays red red turns blue red stays redblue turns red blue stays blue blue stays blue

pH Paper

• Color test to determine the actual pH of a solution.

Buffer• A Solution/chemical that will

prevent dramatic changes in pH.

** Limestone: a natural buffer **

Organic Molecules

• Carbohydrates

• Lipids

• Proteins

• Nucleic Acids

Biological Molecules … you are what you eat.

The Carbon Atom: “The Backbone Atom”

Carbon has 4 valence electrons – bonds with up to four other atoms (H, O, N, or another C)

• Most organic compounds from carbon chains

• Some may form rings of Carbon atoms as well

C C C C C

Recall ……

Formation: Repeating small units combine to

make larger structures

Small building units are called monomersA monomer is like an individual brick

A series of monomers linked together forms a polymer.A polymer is a brick wall

Building Organic Macromolecules

• Monomers link together in a chemical reaction called Dehydration Synthesis (Condensation Reaction)

Water is removed to build larger molecules from smaller ones – covalent bonds will form

Monomer Monomer Monomer Monomer

Water Water Water

Breaking Down Organic Compounds

• Polymers break apart in a chemical reaction called Hydrolysis

Water is added to break down large molecules into smaller ones – covalent bonds will break.

Monomer

Monomer

Monomer

Monomer

WaterWaterWater

Carbohydrates• Cells of the human body obtain most of

their energy from carbohydrates

• Made of Carbon, Hydrogen, and Oxygen in a ration of 1:2:1

• Types: Monosaccharides

Disaccharides

Polysaccharides

Monosaccharides• Single Sugars • These molecules are considered monomers of all the

other larger carbohydrates• Examples:

Glucose: only sugar used for energyFructose: Sugar found in fruit (sweetest)Galactose: Sugar found in milk

• All are Isomers = same formula (C6H12O6), different structure

Disaccharides• Double Sugar Molecules

• Sucrose is composed of glucose and fructose and is transported within plants. (Table Sugar)

• Lactose is composed of

galactose and glucose and

is found in milk.

• Maltose is two glucose molecules; forms in digestive tract of humans during starch digestion.

Polysaccharides

• Large sugars made of many monosaccharide units

• Starch is straight chain of glucose molecules with few side branches.

Function: Energy storage molecule in plants

• Glycogen is highly branched polymer of glucose with many side branches; called "animal starch," it is storage carbohydrate in the liver of animals.

• Cellulose is glucose bonded to form microfibrils; primary constituent of plant cell walls.

• Chitin: A tough, protective, semitransparent substance, primarily a nitrogen-containing polysaccharide, forming the principal component of arthropod exoskeletons and the cell walls of certain fungi.

Lipids• Lipids are large,

NONPOLAR organic molecules that do not dissolve in water

• Lipid molecules have a HIGHER ratio of carbon and hydrogen atoms to oxygen atoms than carbohydrates.

Example: C57 H110 O6

• Lipids store energy efficiently.  They have large numbers of Carbon to Hydrogen bonds, which store more energy than Carbon to Oxygen bonds common in other Organic Compounds.

• Only used for energy when the body has no other immediate energy source.

TRIGLYCERIDES • Three Molecules of Fatty Acids joined to One

Molecule of Glycerol.

• Water is removed by the OH of Glycerol and the H from each fatty acid chains.

Saturated Fats• SATURATED FATS

• NO DOUBLE BONDS BETWEEN THE CARBONS

• “straight” molecule

• SATURATED FATS ARE USUALLY SOLID AT ROOM TEMPERATURE, AND MOST COME FROM ANIMAL PRODUCTS

Unsaturated Fats• UNSATURATED FATS

• SOME DOUBLE BONDS between Carbons.

• This creates a “bend in the molecule.”

• UNSATURATED FATS ARE USUALLY LIQUID AT ROOM TEMPERATURE, AND

MOST COME FROM PLANT PRODUCTS

Phospholipids• Similar to triglycerides, but

contain a phosphate group in place of the third fatty acid chain.

• The phosphate group is polar and capable of interacting with water.

• Membranes that surround cells and surround many cell structures are primarily phospholipid bilayers

Steriods• Classified as lipids

due to its non-polar nature (will not dissolve in water)

• Steroids have a backbone of 4 carbon rings

• Cholesterol is the precursor of several other steroids including several hormones

Dehydration Synthesis in Lipids

Proteins• Proteins are organic compounds composed mainly of

C, H, O, N, and sometimes S.

• They are the most abundant organic compound in the body. (50%)

Common Proteins• Structural proteins include

keratin, which make up hair and nails, and collagen fibers, which are elastic fibers in the skin.

• Actin and Myosin proteins are found in muscle tissues

• Enzymes are functional proteins that act as catalysts

• Hemoglobin is a protein found in blood

• Insulin is a protein that helps regulate blood sugar

• Defense: Antibodies help fight foreign microbes in the body

Structure of Proteins

• Amino Acids are the monomers that condense to form proteins.

• There are 20 different amino acids

• All are similar in structure: only the R-Group is different among the twenty;

gives each different properties

R–G

rou

ps a

re in

blu

e

Dehydration Synthesis of Amino Acids

• A peptide bond forms when the amino group of one amino acid bonds to the carboxyl group of another amino acid

• One water molecule is removed in a dehydration synthesis reaction to form a dipeptide.

• A polypeptide (protein) is the result of many linked amino acids.

Primary Structure Amino acids in a straight chainSecondary Structure Folding and/or coiling; caused by hydrogen bonding between amino acids

Tertiary Structure Additional folding into a more complex structure; more H- bondsQuaternary Structure Involves several subunits together Many polypeptides join to form a

functional protein

Denatured Proteins

• Denaturation: Protein shape is altered

• Once a protein is denatured, it loses its ability to perform its function

• Examples: Acid causes milk protein to “curdle”Heat causes egg white protein to coagulate

Special Proteins: Enzymes• Often serve as catalysts - Speed up the rate of

chemical reactions in living things without being used up in the process

• Enzymes are shaped specifically to fit a certain substrate (chemical that the enzyme works on).

• Fit together at the active site of the substrate like a “Lock & Key”

• This new complex helps a reaction occur faster.

• Enzymes can be re-used many times

Nucleic Acids: DNA & RNA• Very large molecules

that store important information in cells (genetic/heredity info)

• Elements: C, H, O, N, P

• Deoxyribonucleic Acid = DNA; contains info that is essential for all cell functions

• Ribonucleic Acid = RNA; transmits genetic info for the making of proteins

Structure of Nucleic Acids

• Both DNA and RNA are polymers composed of thousands of linked monomers called Nucleotides

• Nucleotides are composed of three parts …1) 5 Carbon Sugar

2) Phosphate Group

3) Nitrogen Base

Polymer structure

• Nucleotides bond to one another by dehydration synthesis to form large polymers

• DNA is composed of two strands that twist into a helix

• RNA is composed of a single strand and forms different shapes, but not helices