TYPE 3 FCA: EXP. ¾ BIOMOLECULES 40 FCA: GIVE ONE EX OF EACH 30 FCA: ESSAY 5 PARAGRAPHS 30

AGENDA Fill in Collins Folder w/ Type 3 ONLY!!! Assignment: BIOMOLECULES I will come around and give you your 1 st Quarter Grades.

TYPE 3 FCA: YOUR LETTER GRADE 30 FCA: WHAT YOU DID GOOD/BAD 40 FCA: 3 GOALS FOR QUARTER 2 30

Type One: Write 5 Observations you see in this picture

Molecules can be represented in many ways

Salt (NaCl)

sodium + chlorine  sodium chloride

Electron arrangement determines the chemical properties of an atom Electrons are arranged in shells –The outermost shell determines the chemical properties of an atom –In most atoms, a full outer shell holds eight electrons

Atoms whose shells are not full tend to interact with other atoms and gain, lose, or share electrons Electron

Ionic bonds are attractions between ions of opposite charge When atoms gain or lose electrons, charged atoms called ions are created –Electrical Attraction: Opposites Attract + / - –Metals + Non-Metals = Compound Na Sodium atom Cl Chlorine atom + Na Sodium ion Cl– Chloride ion

Covalent bonds, the sharing of electrons, join atoms into molecules Atoms share outer energy level electrons with other atoms –Atoms joined together by covalent bonds form molecules –Non-Metals + Non-Metals -- Share Electrons NOT Attraction

Covalent Bonds Share Electrons And Form MOLECULES

Organisms are sensitive to Acidic and Basic conditions A compound that releases H + ions in solution is an acid, and one that accepts H + ions in solution is a base Acidity is measured on the pH scale: –0-6 is acidic –8-14 is basic –Pure water and solutions that are neither basic nor acidic are neutral, with a pH of 7

pH scale Figure 2.15 pH scale Acidic solution Neutral solution Basic solution Increasingly ACIDIC (Higher concentration of H + ) Increasingly BASIC (Lower concentration of H + ) NEUTRAL [H + ] = [OH – ] Lemon juice; gastric juice Grapefruit juice Tomato juice Urine PURE WATER Seawater Milk of magnesia Household ammonia Household bleach Oven cleaner Human blood H+H+ OH –

How Do Cells keep pH at 7? Cells are kept close to pH 7 by BUFFERS Buffers are substances that resist pH change They accept H+ ions when they are in excess and donate H+ ions when they are depleted Buffers are not foolproof

Connection: Acid Rain threatens the environment Some ecosystems are threatened by acid rain Acid rain is formed when air pollutants from burning fossil fuels combine with water vapor in the air to form sulfuric and nitric acids

EFFECTS OF ACID RAIN –These acids can kill fish, damage buildings, and injure trees –Laws, new technology, and energy conservation may help us reduce acid precipitation

BIOMOLECULES CARBOHYDRATES LIPIDS PROTEINS NUCLEIC ACIDS

CARBOHYDRATES Biomolecules made up of SUGAR molecules Major source of ENERGY for organisms 3 Major types of Carbohydrates: –Monosaccharides –Disaccharides –Polysaccharides

MONOSACCHARIDES Made up of only 1 sugar molecule CH 2 O: Carbon, Hydrogen, Oxygen Used by cells for ENERGY Contains a HYDROXYL GROUP (-OH) and a CARBONYL GROUP (C=O)

MONOSACCHARIDES: Sugar Molecules can go from a STRING to a RING !

DISSACHARIDES Form when 2 sugar molecules combine Sucrose

Connection: How sweet is sweet? Various types of molecules, including non- sugars, taste sweet because they bind to “sweet” receptors on the tongue

POLYSACCHARIDES : Many Sugar Molecules bonded together Starch granules in potato tuber cells Glucose monomer STARCH GLYCOGEN CELLULOSE Glycogen granules in muscle tissue Cellulose fibrils in a plant cell wall Cellulose molecules

LIPIDS: Energy storing molecules Made up of carbon and hydrogen DO NOT mix with water

LIPIDS are also called TRIGLYCERIDES TRIGLYCERIDES consists of one glycerol molecule linked to three fatty acids

Phospholipids are a major component of cell membranes Waxes form waterproof coatings Steroids are often hormones Phospholipids, waxes, and steroids are lipids

PROTEINS Proteins are involved in –cellular structure –movement –defense –transport –communication Mammalian hair is composed proteins Enzymes regulate chemical reactions

Proteins are made up of Amino Acids Each Amino Acids contains: –an amino group –a carboxyl group –an R group, which distinguishes each of the 20 different amino acids Amino group Carboxyl (acid) group

How do Proteins Form? Cells link amino acids together by dehydration synthesis The bonds between amino acids are called peptide bonds Amino acid Dipeptide Dehydration synthesis Carboxyl group Amino group PEPTIDE BOND Figure 3.13

NUCLEIC ACIDS Biomolecules that carry all information for a cell: –Blueprints for Protein-Making –DNA & RNA: Control all cell processes.

The subunits of nucleic acids are called nucleotides Phosphate group Sugar Figure 3.20A –Each nucleotide is composed of a sugar, phosphate, and nitrogenous base Nitrogenous base (A)

The sugar and phosphate form the backbone for the nucleic acid Sugar-phosphate backbone Nucleotide