Good Morning! Please sit at your lab table with you lab notebook.

Biology Study of life

Is it ALIVE? Biology is the study of life, but how can you tell if something is alive? All living organisms exhibit certain properties that biologists look for to classify it as alive.

Properties of Life Reproduction Cells Homeostasis Metabolism Heredity All living organisms have the following properties present at some point in their life: Cells Reproduction Homeostasis Metabolism Heredity Evolution Interdependence

Lets start small… What are we made of?

Water Expands when frozen Water is essential for life Living organisms are made mostly of water 70%-90% Resistant to temperature change Homeostasis Expands when frozen Less density than l form Turnover in lakes

Water Adhesive (adhere to surfaces) Cohesive (adhere to each other) The universal solvent Water can dissolve ions and polar molecules. Non-polar molecules do not dissolve well in water (oil, fats). Remember like dissolves like (polar dissolves polar, non-polar dissolves non-polar).

Adhesion Because water molecules are polar, they have a tendency to stick to other polar substances. Glass may carry a partial charge along its surface. That’s why rain droplets stick to windows.

Why does water have these special properties???

…because water is POLAR! Polar molecules have uneven charges. This attracts ions and other polar molecules It is also the reason water is a universal solvent

Capillary Action Polarity water uses cohesive and adhesive properties to climb up capillaries in plants This makes it possible for the tops of the trees to obtain water

Chemistry of Life The Essential Ingredients for Life

Ingredients for Life Water Carbohydrates Lipids Proteins Nucleic Acids

Carbon Compounds Organic (carbon) compounds are found in living things Carbon has four valence electrons ready for bonding Carbon can form chains, chains with branches or rings

What does it all mean???

Carbon can bond with itself and with many other elements Form large organic molecules called biomolecules Small chains are called monomers Large chains made of monomers are called polymers

Carbon Monomer Polymer

Carbon forms: Carbohydrates Lipids Proteins Nucleic Acid

Carbohydrates - made of Carbon, Hydrogen and Oxygen in 1:2:1 ratio (C6H12O6) - major source of energy found in most foods - monosaccharides are simple sugars and the building block of carbohydrates (glucose and fructose) - polysaccharides are large molecules made of many sugars that store energy. plants – starch animals - glycogen

Carbohydrate - Sugar Monosaccharide– glucose polysaccharide- starch

Lipids non-polar molecules Is it soluble in H2O? - fats, phospholipids, steroids, oils, waxes… - important part of cell membranes - lipids are used by cells for energy storage - Insulation

Lipids Saturated fatty acid – no double bonds between carbon- carbon bonds, straight molecule, solid at room temperature Unsaturated fatty acid – double bonds that make the molecule kinked, liquid at room temperature

The way a protein folds is important to its function Proteins - Amino Acids There are 20 different amino acids Amino Acids bonded together form a chain called a polypeptide chain. Amine Group: -NH2 A polypeptide chain folds into a protein The way a protein folds is important to its function Mad Cow Disease

Functions of Protiens Transport: hemoglobin in red blood cells Movement: muscles Structural: membranes, hair, nails Enzymes: cellular reactions

Enzymes Enzymes are proteins Speed up chemical reactions Lower activation energy They work on a specific substrate Some reactions in your body would not occur without enzymes.

Nucleic Acids – Long chains of nucleotides (sugar, phosphate, base) Contain genetic/heredity information in code - DNA- (deoxyribonucleic acid) found in nucleus of cells. Have genes that contain hereditary info (traits). 2 strands - RNA – (ribonucleic acid) can act as an enzyme or help in protein synthesis. 1 strand

Nucleic acids – Genetic Material Nucleic acids are composed of long chains of nucleotides

Identifying Organic Compounds Lab

Introduction The most common organic compounds found in living organisms are lipids, carbohydrates, proteins, and nucleic acids. Substances called indicators can be used to test for the presence of organic compounds. An indicator is a substance that changes color in the presence of a particular compound. In this investigation, you will use several indicators to test for the presence of lipids, carbohydrates and proteins in various foods.

Materials For each organic compound test you need: 5 drops egg white 5 drops lettuce/water 5 drops apple juice 5 drops corn oil 5 drops Spinach/water 5 drops peanut butter 5 drops potato/water 5 drops water Starch test: Iodine solution Sugar test: Benedicts solution Protein: Biuret solution 8 Test tubes Test tube holder Test tube rack Hot plate Brown paper towel Labeling tape

Lipid Test 1. Divide a piece of brown paper towel into 8 equal sections. In each section, write the name of one test substances, as shown. 2. In each section, place a small drop of the identified food onto the brown paper towel. With another paper towel, wipe off any excess pieces of food that may stick to the paper. Set aside for 10-15 minutes 3. Hold paper to light or window. If food sample produces a translucent or see-through spot, there is a presence of a LIPID. 1.Distilled Water 2.Egg White 3.Corn Oil 4. Spinach 5.Peanut Butter 6.Apple Juice 7.Potato & Water 8.Fish

Carbohydrate Test - Starch 1. Label test tubes: water, egg, oil, Spinach, peanut, apple, potato, fish 2. Add 5 drops of each food sample to its proper test tube. 3.Add 5 drops of iodine solution to each test tube and shake. *Iodine will change color from yellow brown →blue black in presence of STARCH. 4. Record data on table. 5. Wash test tubes thoroughly!

Carbohydrate Test - Sugar 1. Set up hot water bath: Fill half the beaker with tap water and heat to a gentle boil. 2. While water bath is heating, fill each cleaned test tube with 5 full drops of the appropriate food sample. 3. Add 10 drops of Benedicts solution and shake. 4. Place test tubes in hot water bath and heat for 3-5 minutes. 5. Caution: Remove test tubes from water bath with test tube holder! *When heated, Benedicts solution will change color from blue → green, yellow, orange, or red in the presence of SUGAR. 6. Record any color changes on data table. 7. Wash test tubes thoroughly!

Protein Test 1. Put 5 drops of appropriate food samples in each labeled test tube. 2. Add 5 drops of Biuret solution to each test tube and gently shake. Caution: Biuret contains NaOH, a strong base. If you splash any on yourself, wash with water and notify your teacher immediately! *Biuret changes color from light blue→blue-violet in the presence of PROTEIN. 3. Record any color change on data table. 4. Wash test tubes thoroughly!

Data chart All should have before and after descriptions! Food Sample Lipid Test Starch Sugar AA or Protein Test Egg white Corn Oil Potato Peanut Butter Water Apple Juice Fish Spinach