BIOMOLECULES BIOLOGY UNIT 2

WHAT IS A BIOMOLECULE? Organic molecule made by living organisms Consist mostly of carbon (C), hydrogen (H), oxygen (O), and nitrogen (N) **96% of your body**

BUT WAIT…WHAT IS AN ORGANIC MOLECULE? Organic Molecules: Contain carbon Considered the “chemicals of life” Associated with living things Inorganic Molecules: Generally do not contain carbon Not the chemicals of life Not associated with living things

MONOMERS VS. POLYMERS Monomers: One molecule that may react with similar molecules to form a chain Polymers: A chain of many monomers that are chemically bonded together

FORMATION OF POLYMERS How are polymers formed? Dehydration Synthesis (Condensation) Two monomers are joined together. Require energy to become polymer Gain H 2 O

BREAKDOWN OF POLYMERS Animation How are polymers broken down? Hydrolysis—the reverse of dehydration synthesis (condensation) Un-linking the chain and breaking it back down to its original monomer units Gain energy to become monomers Lose H 2 O

REVIEW FROM YESTERDAY Monomers=1 single unit Polymers=many units chemically bonded MONOMERS bond to form a POLYMER through DEHYDRATION SYNTHESIS. A POLYMER breaks down into simpler MONOMERS through HYDROLYSIS. ENZYMES help in these processes.

CARBOHYDRATE FOOD EXAMPLES Bread Pasta Donuts Cake Cookies Rice Bagel

LIPID FOOD EXAMPLES Olive oil Vegetable oil Butter Avocado Nuts Cheese Peanut butter

PROTEIN FOOD EXAMPLES Eggs Nuts Meat Fish Beans Peanut butter Shellfish

NUCLEIC ACID FOOD EXAMPLES DNA RNA Meat, Fish, Eggs (came from once-living organisms)

PROTEINS What are proteins? Group of organic molecules that provides structure and facilitates chemical reactions.

PROTEINS Structure: Subunits: Amino acids Connect via peptide bonds Very large molecules Globular or structural (zig-zag shape)

PROTEINS Function: Enzymes (speed rate of chemical reactions) Structural components in cells Mechanical functions in muscles and cytoskeleton (internal cell framework) Cell signaling Immune response

PROTEIN EXAMPLES Enzymes Collagen Elastin Keratin hemoglobin

CARBOHYDRATES What are they? Group of organic molecules that includes sugars, starches and cellulose.

CARBOHYDRATES Structure: Carbon, hydrogen and oxygen in a 1:2:1 ratio Subunits: Monosaccharides, such as glucose or fructose Connected with covalent bonds

CARBOHYDRATES Function: Main source of immediate energy Structural Support Cell Wall Cell Membrane Marker

CARBOHYDRATE EXAMPLE Glucose Fructose Lactose Cellulose Chitin Starch Glycogen

LIPIDS What are they? Organic molecule group including fats and phospholipids

LIPIDS Structure: Subunits: Glycerol + fatty acids Glycerol + fatty acids + phosphate group Insoluble in water Do not form large polymers (2 or 3 fatty acids with glycerol)

LIPIDS Function: Energy storage Insulation Part of cell membrane (phospholipids) Hormones

LIPID EXAMPLE Steroids Cholesterol Wax Fats (unsaturated, saturated, trans)

NUCLEIC ACIDS What are Nucleic Acids? Group of organic molecules including DNA and RNA

NUCLEIC ACIDS Structure: Subunits are nucleotides— 5-Carbon sugar, Nitrogen base and Phosphate group

NUCLEIC ACIDS Function: Storage and retrieval of information: Encode genes Gene expression Contain information to make proteins

NUCLEIC ACID EXAMPLES DNA RNA Guanine Cytosine Thymine Adenine Uracil

WHAT ARE ENZYMES? Proteins that help speed up chemical reactions (catalyst). Many important life processes would not happen (or happen TOO SLOWLY) without enzymes. End with -ase

FACTS ABOUT ENZYMES When an enzyme performs its function, it is not changed. This means it can be used over and over again. An enzyme’s function is determined by its shape, and each enzyme has one specific function. Enzymes have an active site to match up with their substrate, the molecule that attaches to the enzyme.

ENZYMES ARE SPECIFIC

ACTIVE SITE/SUBSTRATE

STEPS TO PROPER ENZYME FUNCTION 1.First, an enzyme and a substrate must be in the same area. 2.Second, the enzyme grabs onto the substrate at a special area called the active site. This area has a special shape and fits around the substrate. 3.Third, catalysis happens. This is when the substrate is changed. It might be broken down or bonded with another molecule to make something new. 4.Lastly, the enzyme lets go. The enzyme is not changed and is ready to do another reaction. The substrate is different now, and it is called the product.

FACTORS THAT CAN AFFECT ENZYME FUNCTION Temperature: Enzymes change shape as temperature changes, so it can mess up the enzyme and cause it to not work anymore. pH levels: Acidity also affects an enzyme’s shape. Inhibitors: These slow down or stop the activity of an enzyme by bonding to the protein changing the shape of the enzyme. Concentration: Too many substrates and not enough enzymes will cause the reactions to occur more slowly The process of changing an enzyme’s shape is called denaturing. (temperature and pH)

ENZYMES IN HUMAN BODY Salivary Amylase: enzyme that catalyzes the hydrolysis of starch into simpler compounds helps begin the process of digestion in the mouth present in human saliva if it were not present, you would not be able to break down complex sugars into simpler sugars in your mouth, which would make digestion harder

ENZYMES IN HUMAN BODY Pepsin Located in stomach juice Helps breakdown proteins like those in dairy, meat, nuts, and eggs Small amounts are also found in the intestine and the blood stream Without pepsin, the body would be unable to breakdown proteins into their peptide and amino acid parts

ENZYMES IN HUMAN BODY Lactase Found in the small intestine, liver, and kidney Breaks down the milk sugar, lactose into simpler sugars (glucose and galactose) Very abundant in infants Without lactase, the body is unable to breakdown milk products. People without lactase are said to be lactose intolerant. They may have to avoid all dairy products or take medications with synthetic lactase to help them digest dairy products.

ENZYMES IN HUMAN BODY Catalase Found throughout the body, usually in cell organelles called peroxisomes Breaks down hydrogen peroxide into water and oxygen Hydrogen peroxide is a waste product of cells, but it is toxic to the body. So, without catalase, hydrogen peroxide would build up and cause cell and tissue damage.