Cell Processes Chapter 9 Chemistry of life Moving Cellular Materials Energy for life

Chemistry of Life Mixtures Organic compounds Carbohydrates Nature of Matter Atoms Elements Compounds and Molecules Molecular compounds Ionic compounds Mixtures Organic compounds Carbohydrates Lipids Proteins Nucleic Acids Inorganic Compounds Importance of water Characteristics of water

Nature of Matter All things in universe contain matter and possess energy Matter is anything that has mass and takes up space Energy is anything that brings about change

Atoms Matter is made up of atoms Atoms are the smallest part of an element There are 92 naturally occurring elements on earth Composed of a nucleus in center where protons and neutrons are found Surrounding the nucleus are electrons Protons are positively charged particles Electrons are negatively charged particles Neutrons have no charge (neutral)

Structure of Atoms Electons (-) Protons (+) Neutrons (0)

Elements When matter is made up of only one kind of atoms it is an element (pure substance) Each element has its own symbol (one or two letter symbol) H, He, O , Na Organized on periodic table by mass, number of protons, and symbols Matter is mostly in combinations with other elements (NaCl), H2O Some matter is composed of same elements O and C make 83% of human body S,P,O,N,C and H make up 99 % of living matter

Compounds and Molecules Molecular compounds have elements that share their electrons The elements that share electrons in a molecule take on different chemical properties that the elements themselves H and O share electrons to form H2O, in a proportion of 2 H to every 1 O, H2O is different than the elements H or O gas

Ionic compounds Atoms are normally neutral Sometimes atoms loose or gain electrons and become either positive or negative charged Ions are charged atoms (+ or -) Atoms that combine as result of these charged particles produce ionic compounds Ionic compounds are important in organism because they send messages, transport O, move things in and out of cell

Mixtures Sometimes substances combine but don’t change their own identities which are called mixtures (salt water) Can be solid, liquid or gas or combination of each Solutions are mixtures that are evenly mixed NaCl andH2O are solutions which retain own characteristics Suspensions are special solutions that some of the substances settle out of solution Blood is an example

Organic Compounds Always contain Carbon and Hydrogen and associated with living things Organic compounds groups are: Carbohydrates: supply energy, made of sugars and starches (C,H,O) Lipids: don’t mix with water, fats and oils stored release larger amounts of energy (C,H,O,P) Proteins: made of amino acids that are building blocks of many structures in organism, (C,H,O,N,S) enzymes are special proteins that regulate all chemical reactions in cells

Organic Compounds Nucleic Acids: molecules that store coded information in cells (C,H,O,N,P) Directs cells activities and genetic information DNA and RNA

Inorganic Compounds Most are made from elements other than Carbon Few atoms in molecules Needed by organisms to carry out life functions H2O, Calcium Phosphate (CaPO4), Hydrochloric Acid (HCl) , Sodium bicarbonate (NaCO3)

Water: Importance and Characteristics Life thought to began in water Living organisms are composed of at least 50% water and depends on water to live Water necessary for plants to grow and live Chemical reactions in living things takes place in water solutions and materials are moved in water solutions in cells

Special Water Characteristics Water atoms are arranged so that there is a negative and positive area on the molecule These positive and negative poles causes it to act like a magnet to other water molecules A strong film is formed allowing small insects to walk on water When heat is added to water, water molecules are so strongly attached to each other the temperature changes slowly and acts like an insulator (constant temperature inside cells)

Water Molecules

Special Water Characteristics When water freezes, ice crystal forms, and the spacing between molecules remain constant Distance between molecules in frozen states is farther apart, ice floats Water freezes from top down and provides an insulation from extremely cold temperatures allowing organisms to survive in cold water under ice

Moving Cellular Materials section 2 Passive Transport or Active Transport Endocytosisi or Exocytosis

Passive Transport Cell membrane acts like a screen to allow certain things in or out of cell When no energy is required to transport material across the cell membrane it is called passive transport There are 3 methods materials are moved through the cell : diffusion, osmosis, facilitated diffusion

Diffusion Movement of molecules from areas of greater concentrations to areas of less concentrations is called diffusion Smoke moving in a room Movement of molecules continue until equilibrium is met (evenly distributed) Diffusion of oxygen in blood is moved into red blood cells in lungs and deposited in your toes.

Difussion

Osmosis Diffusion of water across cell membrane is osmosis Plant cells will become limp if placed in salt water Animal cells will swell up in presence of water and will burst if too much water enters the cell

Facilitated Diffusion Sugar molecules are large and need transport proteins to help them enter cells Facilitated diffusion is the process of passive transport that allows large molecules to pass through cell membrane Transport proteins help cells allow large molecules like sugar molecules in without using energy as it crosses cell membrane

Facilitated diffusion

Active Transport Active transport is the movement of molecules across the cell membrane that requires energy Roots of plants always take in minerals into cells already high in concentration (this is opposite of diffusion) Requires energy to get them into cells Transport protein is required to move across cell membrane

Endocytosis Process of allowing substances into a cell by surrounding it with the cell is called endocytosis Finger stuffed in balloon is an example of a cell surrounding a substance Vesicles are formed when cell membrane folds in on itself: they then are moved and stored in cells to be used

Exocytosis Opposite of endocytosis Large materials are removed from cells Materials are packaged in vesticles and fuse with cell membrane and are diffused through cell membrane out of cell Cells in your stomach release chemicals that help digest food Page 259 reference

http://highered.mcgraw-hill.com/olc/dl/120068/bio02.swf

Energy for Life section 3 Trapping and using energy Photosynthesis Producing carbohydrates Storing carbohydrates Cellular respiration Breaking down carbohydrates Fermentation Related processes

Trapping and Using energy Metabolism is the total of all the chemical reactions that take place in organisms Enzymes are needed to allow organisms to utilize food. They help make food usable Enzymes causes larger molecules to break down into smaller molecules and enzymes are still available to break down other large molecules (page 261)

Photosynthesis Producers (plants) produce their own food using the sun and storing the food in form of sugars and carbohydrates Releases oxygen as a by product

Producing Carbohydrates Plants have organelles called chloroplast that carry green pigment called chlorophyll that captures the suns energy and transforms it to food that stores energy in chemical bonds Carbohydrates and sugars are produced by the plants Oxygen is given off

Photosynthesis equation Plants utilize sun to produce glucose C6H12O6

Storing Carbohydrates During photosynthesis, more food is produced than used for energy and it is stored as carbohydrates and starches Animals eat plants and break down these chemical bonds of carbohydrates and starches to get their energy

Cellular Respiration During cellular respiration chemical reactions occur that break down food into simpler substances and release their stored energy when the bonds are broken Opposite of photosynthesis as the product of photosynthesis is the materials used in cellular respiration and visa versa: Carbon dioxide and water is released

Fermentation Fermentation is a process when cells do not have enough oxygen for cellular respiration Glucose is broken down and energy is released in cellular respiration in the mitochondria When the demand for energy is too great, the cytoplasm sometimes break down glucose When this happens lactic acid is produced causing burning and soreness in muscles

Fermentation Bacteria uses fermentation to produce their energy The lactic acid produced produces yogurt and cheeses Yeast cells use fermentation that release alcohol and carbon dioxide as wastes in bread making

Relationship of photosynthesis, cellular respiration and fermentation Producers use photosynthesis to produce food All living things use respiration or fermentation to release energy stored in food Photosynthesis and cellular respiration use each of the other products as their source of production

CO2 + H2O C6H12O6 + O2 Light energy Photosynthesis