Cell Processes (chemistry and respiration) Organic compounds they always contain carbon 4 types that you need to know: Lipids (fats, oils and waxes), Carbohydrates, Proteins and nucleic acids Inorganic compounds Normally do not contain carbon although there are Exceptions: Carbon dioxide and Calcium carbonate are two of them CO2 and CaCO3 4 types H2O, salts, bases, and inorganic acids Carbohydrates: Sugars and starches they serve as energy and food source compounds Made of carbon and hydrogen and oxygen Types of carbohydrates: Monosaccharides the most simple ones hence the name mono Glucose - C6 H12 O6 Fructose Sugars end in OSE Chitin makes up the shell or exoskeleton in insects Disaccharide two sugar molecules (monosaccharides) 2 Glucose molecules = maltose or C12 H22 O11 notice the 2:1 ratio Sucrose Polysaccharides complex carbohydrates made of chains of monosaccharides 1 starch food storage in plants 2 cellulose cell walls in plants - forms a tough structural support 3 glycogen food storage in animals All three are made of glucose Proteins - Required for new growth, replaces worn out cells, transport proteins act as a buffer to acidity and tissue fluids Made of smaller units called amino acids Carbon nitrogen bond We get proteins from meats Enzymes and hormones are made of proteins Amino acids building blocks of protein Made of an amino group NH2 There are 20 different ones in humans different combos Amino acids in the cell: Put together proteins, provide glucose, provide nitrogen to build other amino acids, provide energy When sugar and carbohydrates are low
Increase stored energy Too much protein not always needed For each protein an exact sequence or recipe must be followed a wrong amino acid insert is disastrous sickle cell anemia Enzymes a protein substance that is necessary for most chemical reactions occurring within living cells - increase rates of reactions that catalyze by at least one million times used again and again lock and key model) Catalyst a substance that brings about a reaction without being changed itself. Enzymes are organic catalysts Substrate the substance that enzymes act upon Enzyme structure large complex proteins One or more polypeptide chains Enzymes end in ASE lipase, lactase, maltase Maltase breaks down to maltose (2 glucose molecules) Lipase breaks down lipids Protease breaks down proteins How enzymes work: Substrate substances that combine with an enzyme they can either be joined or split Each enzyme has a specific shape and only works with certain molecules (very specific) After a reaction takes place by the enzyme it is free to work on another reaction enzyme structure is unchanged Active site is the area where the enzyme where the reaction takes place Coenzyme the non-protein organic substance necessary to the function of certain enzymes some vitamins Factors affecting enzyme reaction rates Temperature as temp. increases so does the rate of reaction The temp. at where the enzyme is most efficient is optimum A high temp. (above 40 C) enzyme molecule is distorted (active site changed) Condition known as denaturation renders enzyme ineffective PH indicates H+ concentration - the scale runs from 0 14 (0 acid, 14 base) 7 is neutral and most enzymes work best at neutral conditions gastric enzymes (stomach) work best at low ph or acidic 0-6 Concentration of enzymes and substances When excess substrate is added the rate of reactions increased
Lipids fats and oils and waxes - made of C, H, O Serve as reserve energy for organisms Lipids are solid at room temperature bacon grease (fats) Lipids that are liquid are oils Waxes are fatty acids and alcohol Components of cell membrane Cholesterol builds up in veins, arteries and heart causes heart attacks/stroke It also is an essential compound found in most animal tissue (fat in the blood) Saturated fat increased heart attacks, cholesterol levels Tends to be solid at room temp. Unsaturated decreased HA, Cholesterol levels tends to be oils or liquids at room temp. Wild game vs. Cows Nucleic acids organic compounds that contain phosphorous, nitrogen, carbon, hydrogen and oxygen - Storage, transmission and expression of genetic info. Directs and controls the develop and activities of the cell DNA (deoxyribonucleic acid) made of repeating units called nucleotides Coil molecule or double helix - Sugar is deoxyribose RNA (Ribonucleic acid) involved in protein synthesis only one chain single helix - sugar is ribose DNA contains chemical code required for amino acid to form protein RNA assembles amino acids into proteins Other inorganic molecules lack the combo. Carbon-hydrogen Living organisms contain salts, water, inorganic acids and bases Water most important inorganic compound 65% of human body weight Polar molecule regions of a positive charge and a negative charge Undergoes cohesion and adhesion Co the force of attraction between molecules of the same substance Responsible for holding drops of water together Helps water store heat better than other liquids Heat makes water mol. move faster can only move faster if cohesion is overcome Some heat moves mol. most of the heat breaks cohesion water is able to handle a lot of heat without abrupt temp. change Ad Attraction of mol. of one substance to Mol. of another Substance - Makes water a great solvent universal solvent Water is the Mickey Mouse Mol. and is polar The electrons of a water mol. are not equally distributed
More electrons surround the oxygen atom making that side negative while the Hydrogen atoms -Have a more positive charge Hydrogen bonds electrostatic attractions between slight negative and slight positive charges Hydration shells layers of water surrounding and loosely bound to an ion in Solution NaCl Capillary action The tendency of water to move up a small tube Due to adhesion between water and the tube and cohesion between water mol. Plays important role in transport of water through the roots of plants Passage of materials through the cell membrane Selective permeability: The cell only allows certain substances to pass through while preventing others from doing so this helps to protect the cell Diffusion:Also called passive transport Substances move from an area of high concentration to an area of low concentration Example: liquid sulfur in the hallway will eventually spread through the whole school Facilitated Diffusion: As the name suggests this is diffusion that has help to make it easier The cell membrane has channels like escorts that help substances across Ex: sodium Osmosis: This process is the diffusion of water the term only applies to water! Water moves from areas of high concentration to lower concentration and also in accordance with gravity Osmotic Pressure: The amount of pressure exerted by the water an item contains Effects of Osmosis Isotonic solution (iso means same) pressure is the same on either side of a Membrane Hypotonic solution a solution that has less pressure than the surrounding solution so water tends to flow in towards it Hypertonic solution a solution where pressure is higher than the surrounding medium causing water to flow from it
Passive transport: Transport of materials that does not require energy riding a boat Downstream from high concentration to low concentration Diffusion and osmosis are examples of passive transport Active transport: Transport of materials that requires energy to be used in order to move Substances paddling upstream against the current Transports materials from a lower concentration to a higher concentration Opposite of what normally happens Endocytosis: Refers to the bulk uptake of materials through the plasma membrane and into the cell there are two kinds pinocytosis (means cell drinking) and uses a liquid to dissolve solid particles taken in Phagocytosis (means cell eating) refers to a cell engulfing a solid particle White blood cells engulf bacteria in this manner Exocytosis (exo means exit) getting rid of wastes from the cell Cellular respiration Enzyme controlled reactions where energy from glucose is made available --- ATP adenosine triphosphate The energy is used for metabolic activities that require energy active transport ATP can be used in any part of the cell that needs energy W/ in autotrophs and heterotrophs and from microorganisms to Humans Two types of respiration: Aerobic and anaerobic Anaerobic respiration in the absence of free oxygen (w/out O) Glucose is partially broken down or oxidized Energy is obtained w/out oxygen In yeast pyruvic acid is converted in to ethyl alcohol and CO2 CO2 makes bread dough rise (fermentation) In bacteria pyruvic acid is converted into lactic acid Muscle fatigue - When humans run out of oxygen they switch to anaerobic respiration for a short period of time Organisms that use anaerobic respiration are called anaerobes
Aerobic respiration the requires oxygen. Glucose is completely oxidized to CO2 and H2O The release of energy in the presence of oxygen ---- happens mostly in the mitochondria The end product is 36 ATP molecules of ATP much more efficient By using oxygen glucose can be completely broken down to CO2 and H2O Organisms that use aerobic respiration are called aerobes Formula is: C6H12O6 + O2 ---- 6CO2 + 6H2O + 36 ATP Photosynthesis The process by which plants capture and transform energy from sunlight into chemical energy. Source of most O2 in the air. Most of the chemical energy (glucose) available to all organisms Opposite of respiration Formula is: C6O2 + 12H2O -------------------- C6H12O6 + 6H2O + 6O2 Recycling Obviously it is important to recycle our resources because they are limited Things that are recycled are paper, aluminum, glass, plastic Biodegradable Things that break down easily (paper) in the environment Plastics may take several hundred years to break down causing pollution the entire time