Journal – 10/24/11 What are some of the nutrients that your body needs to function? Are these in your favorite foods?

Ch 4 & 5: Biochemistry

Life requires about 25 basic elements… 96% of Living Matter O C H N Other 4% is MOSTLY Ca P K S Trace Elements Life requires about 25 basic elements… 96% of Living Matter O C H N Other 4% is MOSTLY Ca P K S Trace Elements

Water Polar molecule - uneven sharing of electrons Forms hydrogen bonds Likes to stick to other water molecules (cohesion) Likes to stick to other surfaces (adhesion) Low density of ice makes it float Universal solvent

pH Scale - p. 85 Buffers - substances that resist changes in pH

Biomolecules Are very large Monomers (small molecules) are linked together to make polymers (large molecules)

Physical Science Review Read Ch 4, pages and take your own notes. Answer the following questions in your notebook: 1.Know the difference between elements and compounds 2.Know what an atom is and what it is comprised of 3.Know the different types of chemical bonds 4.Know what a chemical equation represents

Journal 10/25/11 How would you describe bonding between polar molecules? What is this type of bonding called?

Parts of an atom Nucleus Protons (+) Neutrons(none) Orbitals Electons (-)

Ionic vs. Covalent Equal sharing of electrons Unequal sharing of electrons Polar molecules

Ionic Bonds Forms ions Anion (negative) Cation (positive)

4 categories: 1.Carbohydrates 2.Lipids 3.Proteins 4.Nucleic Acids

Carbohydrates Monomers are sugar molecules Are ring-shaped Ex: glucose, fructose, maltose Are a cell’s main fuel Starch is a long chain of sugars (plants) Glycogen is excess sugar stored in the liver (animals) Cellulose is many chains linked into sheets that can’t be digested by people (plants)

Lipids (fats) Monomers - one glycerol & 3 fatty acids; don’t dissolve in water Serve as long term energy storage Saturated: maximum hydrogens; heavy; ex: butter, animal fat Unsaturated: less than maximum hydrogen; ex: light, oil

Proteins Monomers - 20 different amino acids They make hair, muscles Are enzymes that control chemical reactions They lower the activation energy needed to get a reaction going (p frogs); proteins that do this are called catalysts (p. 104)

Proteins as Enzymes Enzyme – a protein catalyst that controls the rate of a chemical reaction without themselves being affected by the reaction. Catalyst – something that speeds up a chemical reaction. Substrate – the specific molecule (lock) that the enzyme (key) fits Active site – place on the enzyme where the substrate and enzyme form a chemical bond.

Enzymes You want to buy a Xbox – MSRP $300 Get a job $7/hr x 2 hours a day How much do you make a week? (M-F) $70 In four weeks you have earned $280 Best buy has a 1-week coupon for 10% your purchase…. You have enough money!

Enzymes All reactions “cost” energy to start An enzyme acts as a coupon…lowers the cost…or the amount of energy needed = less work or energy

Nucleic Acids (DNA, RNA) Monomers - nucleotides; are made of a sugar, phosphate, and a base They control heredity – carry genetic information

2 reactions you need to know: Dehydration synthesis: removing water to put monomers together Hydrolysis: adding water to a polymer to break it into monomers

Review: Things to Remember.. What does this represent? # Energy Diversity

Nitrogen Cycle What is nitrogen fixation? Converting Nitrogen gas (N 2 ) into ammonia or ammonium (form useable by living organisms) REVIEW the nitrogen, water, and carbon cycles

Commensalism, mutualism, and parasitism Mutualism Both organisms are helped Commensalism One is helped, the other is not harmed Parasitism One is helped, one is harmed

Review Biomes Questions? Biotic vs. Abiotic factors Levels of organization