Transcript Goal 2
Goal 2 Physical, chemical and cellular basis of life. 2.01 Organic Molecules • Contain carbon • Molecules of living things (or once living) • Make up all living things • Examples: mouse, wood, apple, bread, paper, bacteria Carbohydrates • Long chains of simple sugars (monosaccharide) form polysaccharides • Monosaccharides (simple • sugar): glucose, fructose, galactose, ribose Polysaccarides (complex): cellulose, glycogen, starch Proteins • Proteins – long chains • • • of amino acids Joined by peptide bonds Forms a polypeptide (Examples are enzymes, insulin and hemoglobin) Lipids • Subunits are fatty • • • acids and glycerol Fats, Oils, and Waxes Phospholipids, Triglycerides, Cholesterol Cell membranes, sex hormones Nucleic Acids • DNA and RNA • Subunits are nucleotides • Carries genetic • information Composed of sugars, phosphates, and nitrogenous bases • DNA (A,C,T,G) • RNA (A,U,C,G) Functions of macromolecules Carbohydrate energy Proteins structure, growth, repair Lipids long term energy storage, cushioning, insulation Nucleic Acids instructions on how to make proteins Food Tests Benedict’s solution is a test for monosaccharides. It starts blue and turns red if heated. Food Tests Iodine is a test for starch. It starts as a rust color and turns black or blue/black. Food Tests Lipids turn brown paper translucent. Food Tests Proteins Biurets turns purple. 2.02 Structure and Function of Cells Cells are the basic unit of all living things. Cell Organelles Nucleus – contains DNA, regulates the functions of the cell. Plasma (cell) membrane - regulates what goes into and out of the cell. Mitochondria – where cellular respiration occurs. Cell Organelles Ribosomes – where protein synthesis occurs. Cell Organelles Cell wall – made of cellulose, protects plant cell and gives it shape. Vacuoles – store food, water or waste. Large in plant cells, small in animal cells. Chloroplast – where photosynthesis occurs. Microscopes How do you focus? How do you let more light in? When would you need more light? How do you go from low to high power? What does the microscope do to your image? Magnification Eyepiece x Objective = Total Magnification Examples: 10x x 4x = 40x 10x x 10x = 100x Hierarchy of cell organization Cells Tissues Organs Organ systems Structure and Function Nerve cells structure is well suited to carrying nerve impulses through the body. Structure and Function Red blood cells smooth disk shape is well suited to traveling through blood vessels. Structure and Function Muscle cells need a great deal of energy, so they have many mitochondria located in them. Plants vs. Animal Cells Plant cells Animal cells Cell wall Large vacuoles Chloroplasts Rectangular shape No cell wall Small vacuoles No chloroplasts Any shape Cell Communication Messages can travel from one nerve cell to another. Cell Communication G proteins act like relay batons to pass messages from circulating hormones into cells. A hormone (red) encounters a receptor (blue) in the membrane of a cell. A G protein (green) becomes activated and makes contact with the receptor to which the hormone is attached. The G protein passes the hormone's message to the cell by switching on a cell enzyme (purple) that triggers a response. Cell Communication • Steroid hormone action 2.03 Cell Transport and Homeostasis Homeostasis: maintaining a stable internal environment Example – regulation of temperature Sweating Blood vessels dilate Example – regulation of temperature Shivering Blood vessels constrict Hair stands on end Examples – pH of blood Buffers in blood help to keep blood from becoming too acidic or too basic. Example – blood glucose level Insulin removes glucose from your blood by turning it into glycogen in your liver and muscles. Glucagon puts glucose into your blood by converting glycogen into glucose. Example – water balance Too much water? Urinate frequently and it is very dilute. Too little water? Urinate infrequently and it is very concentrated. Transport (types) 1. Passive transport (no energy) a. Diffusion b. Osmosis 2. Active transport (energy) Diffusion - The movement of molecules from an area of high concentration to an area of low concentration. Osmosis Diffusion of water thru a membrane. Active Transport Movement of molecules from an area of low concentration to high concentration. Requires Energy! Semi-permeable membrane Allows small molecules to pass through but not large ones. Semi permeable membrane Examples of transport 1st picture – RBC’s in salt water 2nd –RBC’s in slightly salty water 3rd – RBC’s in distilled water Examples of transport 2.04 Characteristics of Enzymes • Specific fit with substrate • • • • so each enzyme has special job.(lock and key) Meet at enzymes active site. Made of proteins. Enzyme can be re-used after it has done its job. Catalyst. Necessary for all biochemical reactions. Effects of the environment on enzymes • Environmental • changes can destroy enzymes (change their chemical structure and make them ineffective) pH, temperature 2.05 Respiration and Photosynthesis Function of ATP • Adenosine Tri-phosphate • Made from ribose, adenine, and three phosphate • • • molecules Energy storage molecule. Energy is stored when phosphate bond is formed, and released when the bond is broken (makes ADP) Important cycle in respiration and photosynthesis ATP When high energy phosphate bond is broken energy released and ADP made. Cellular Respiration All living organisms do respiration Anaerobic Respiration • Without Oxygen • 2 Types – 1) alcoholic fermentation produces alcohol (yeast) – 2) lactic acid fermentation produces lactic acid (muscle cells and bacteria) Aerobic Respiration With oxygen More efficient Occurs 24/7 C6H12O6 + O2 CO2 + H2O + ATP What might effect the rate of respiration? Compare and Contrast Anaerobic Respiration Without oxygen Cytoplasm 2 ATP Yeast, bacteria 24/7 Aerobic Respiration With oxygen Mitochondria 36 ATP Multicellular organisms 24/7 Photosynthesis • How plants take energy • • • from sun and make glucose Only occurs during the day Plants, algae, blue-green bacteria What might effect the rate of photosynthesis?