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• ORGANIC MOLECULES - Organic compounds contain carbon and are found in all living things.
• Carbohydrates

  major source of energy and include sugars and starches

  made up of carbon, hydrogen, and oxygen with a 2:1 ratio of hydrogen to oxygen

  plants and animals use carbohydrates for maintaining structure within the cells
• • Proteins

  Nitrogen-containing compounds made up of chains of amino acids

  20 amino acids can combine to form a great variety of protein molecules

  can compose enzymes, hormones, antibodies, and structural components
• Lipids

  water-insoluble (fats and oils)

  made up of carbon, hydrogen and oxygen; composed of glycerol and fatty acid

  provide insulation, store energy, cushion internal organs, found in biological membranes

  saturated (with hydrogen, single bonds, see example ) and unsaturated (double bonds)
• Nucleic Acids

  direct the instruction of proteins

  genetic information an organism receives from its parents

  two types: DNA (deoxyribonucleic acid) and RNA (ribonucleic acid)
• Chloroplast – capture solar energy for

  photosynthesis (plant cells, some algae)
• Golgi Body – package, distribute products
• Lysosomes – digests excess products

  and food particles
• Mitochondria – transform energy through

  respiration
• Nucleus - Contains DNA which controls cellular activities
• Ribosomes - produces proteins
• Vacuole - store substances
• cell (plasma) membrane - phospholipids bilayer that protects and encloses the cell; control transport maintains homeostasis
• cell wall - rigid second layer that protects and encloses the cell (plant cll and some bacteria)
• cytoplasm - fluid like substances that contains various membrane-bound structures (organelles) that perform various functions
• endoplasm reticulum - site of chemical reactions

  rough : contains ribosomes

  smooth : lipids production
• cytoskeletal - provides internal structure

  microfilaments : fibers

  microtubes : cylinders
• CELL TYPES:

  • Unicellular – organism that exists as a

  singular, independent cell
• Multicellular – organism that exists as

  specialized groups of cells; cells are

  organized into tissues that perform the

  same function; tissues form organs and
• Prokaryote – has nuclear material in

  the center of the cell, but is not enclosed

  by a nuclear membrane; no membrane-

  bound organelles; found in bacteria and

  blue-green bacteria
• Eukaryote – contain a clearly defined

  nucleus enclosed by a nuclear

  membrane and membrane-bound

  organelles; found in plants, animals,

  fungi, and protists
• Passive Transport – movement of substances across the plasma membrane without the use of the cell’s energy (with the concentration gradient)
• DIFFUSION – movement of substances across the plasma membrane from an area of high concentration to an area of low concentration
• OSMOSIS – diffusion of water across the plasma membrane from areas of high concentration to areas of lower concentration
• FACILITATED TRANSPORT – a carrier molecule embedded in the plasma membrane transports a substance across the plasma membrane following
• Active Transport – movement of substances across the plasma membrane that requires the use of the cell’s energy and carrier molecules; substances

  are moving from an area of low concentration to an area of higher concentration (against the concentration gradient)
• ENDOCYTOSIS – large particles are brought into the cell
• EXOCYTOSIS – large particles leave the cell
• HOMEOSTASIS – internal equilibrium; the plasma membrane regulates what enters and leaves the cell; a selectively permeable membrane only allows

  certain substances to pass through
• HYPOTONIC – water moves in; cell bursts
• HYPERTONIC – water moves out; cell shrivels
• 3. ISOTONIC – no net movement; cell maintains equilibrium
• BIOCHEMICAL REACTIONS: chemical bonds are formed and broken within living things creating chemical reactions that impact the ability to maintain

  life and carry out life functions
• Cellular Respiration – food molecules are converted to energy; there are three stages to cellular respiration; the first stage is called

  glycolysis and is anaerobic (no oxygen is required); the next two stages are called the citric acid cycle and the electron transport chain and

  are aerobic (oxygen is required)
• Photosynthesis – plant cells capture energy from the Sun and convert it into food (carbohydrates); plant cells then convert the

  carbohydrates into energy during cellular respiration; the ultimate source of energy for all living things is the Sun (in Chemosynthesis,

  organisms use sulfur or nitrogen as the main energy source)
• ATP – ATP is a molecule that stores and releases the energy in its bonds when the cell needs it; removing a phosphate group (P) releases

  energy for chemical reactions to occur in the cell and ATP becomes ADP; when the cell has energy, the energy is stored in the bond when

  the phosphate group is added to the ADP
• Fermentation – when cells are not provided with oxygen in a timely manner, this process occurs to continue producing ATP until oxygen is

  available again; glucose is broken down; there are two types of fermentation
• Aerobic Respiration –

  requires the presence of oxygen

  release of energy from the breakdown of glucose (or another organic compound) in the presence of oxygen

  • energy released is used to make ATP, which
• Anaerobic Respiration –

  occurs in the absence of oxygen

  breakdown of food substances in the absence of oxygen with the production of a small amount of energy

  produces less energy than aerobic respiration

  often called fermentation

  • seen as an adaptation for organisms that live in environments that lack oxygen
• ENZYMES:

  Enzymes are special proteins that regulate nearly every biochemical reaction in the cell. Different reactions require different enzymes.

  Enzymes function to:

  Provide energy to cells

  Build new cells

  Aid in digestion

  Break down complex molecules (“substrate” = reactant)

  Catalysts (speed up chemical reactions without being used up or altered)

  • Factors that affect enzymes: pH, temperature, and quantity