Bio 115 Study Guide Exam 1

Bio 115 Exam 1 Study Guide These topics will be on the exam.

? What are the tenets of cell theory? • Cells are the basic structural and physiological units of all living organisms. • Cells are both distinct entities and building blocks of more complex organisms. OR • All living organisms are composed of one or more cells, Cells are the basic units of structure and function in an organism, and Cells come only from the reproduction of existing cells. OR • All cells come from preexisting cells. All cells are similar in chemical composition.

• Most of the chemical reactions of life occur in aqueous solution within cells. • Complete sets of genetic information are replicated and passed on during cell division. • Viruses lack cellular structure but remain dependent on cellular organisms. ? What is homeostasis? • The maintenance of a steady state, such as a constant temperature or a stable social structure, by means of physiological or behavioral feedback responses ?

Know the levels of organization of life from the lowest to the highest levels Atoms>molecules>organells>cells>tissues>organs>organisms/individuals>populations>communities>ecosystems ? Genome distance and common ancestors Genome: The complete DNA sequence for a particular organism or individual ? What are the 3 domains? 1)archaea ,bacteria, species ? Heterotrophs vs. autotrophs

Heterotrophs: (humans) An organism that requires preformed organic molecules as food Autotrophs: (plants) An organism that is capable of living exclusively on inorganic materials, water, and some energy source such as sunlight (photoautotrophs) or chemically reduced matter ? What does the null hypothesis say and how does that relate to control and experimental group outcomes? ? Know how to determine the number of protons, neutrons, and electrons in an atom Atomic # = # of protons Electrons are the same as protons Atomic#-Atomic mass= neutrons.

? What is an isotope?

What is an isomer? Isotope: same # of protons but different # neutrons Isomer: Molecules consisting of the same numbers and kinds of atoms, but differing in the bonding patterns by which the atoms are held together. ? Know the differences between the various kinds of bonds, i. e. , covalent bonds, ionic bonds, hydrogen bonds, and van der Waals forces Covalent Bond: 2 atoms sharing 1 or more pairs of electrons (strongest bond) Ionic Bond: attraction of opposite charged ions (NaCl) Hydrogen Bond: weak attraction shared between 2 electronegative atoms.

Van der Waals: Weak attractions between atoms resulting from the interaction of the electrons of one atom with the nucleus of another. This type of attraction is about one-fourth as strong as a hydrogen bond.

? How many electrons are in the first and second shells? Be able to determine how many electrons are in the outer shell 1st shell: 2 max 2nd shell: 8 max 3rd shell: 16 What kind of bond is water made from? Partial positive and negative charges of water Hydrogen & oxygen (h2o) ? What happens to salt when it is placed in water? ? Cohesion vs. adhesion Cohesion-the tendency of molecules to stick together

Adhesion- ? Solutions, solvents, and solutes Solutions: A substance that is dissolved in a liquid (solvent) to form a solution. Solvents: Liquid in which a substance (solute) is dissolved to form a solution Solutes: A substance that is dissolved in a liquid (solvent) to form a solution ? Definitions of acids and bases Acids: A substance that can release a proton in solution. Base: A substance that can accept a hydrogen ion in solution ? How are hydrogen ion concentration and pH related? ? What do buffers do? A substance that can transiently accept or release hydrogen ions and thereby resist changes in pH. Know the building blocks or monomers of nucleic acids, proteins, carbohydrates, and lipids Nucleic Acids: formed from four kinds of nucleotide monomers linked together in long chains Proteins: formed from different combinations of 20 amino acids, all of which share chemical similarities.

Carbohydrates: form giant molecules by linking together chemically similar sugar monomers (monosaccharide’s) to form polysaccharides. Lipids: form large structures from a limited set of smaller molecules, but in this case noncovalent forces maintain the interactions between the lipid monomers ? Primary vs. econdary vs. tertiary vs. quaternary protein structure Primary: chain of amino acid monomers linked by peptide bonds Secondary: hydrogen bonds create ? -helices (hair) and ? -pleated sheets (nails) which provide flexibility in strength Tertiary structure: hydrogen bonds and disulfide twist things around into more complex shapes (lysozyme in digestion) Quaternary: four subunits of tertiary structures bond together (heme in hemoglobin in blood) also affected by temperature, pH, and salt concentration ? Storage polysaccharides in plants and animals ? Structural polysaccharides in plants and animals Differences between triglycerides (fats and oils), phospholipids, and steroids Triglycerides: A simple lipid in which three fatty acids are combined with one molecule of glycerol.

Phospholipids: A lipid containing a phosphate group; an important constituent of cellular membranes. Steroids: Any of a family of lipids whose multiple rings share carbons. The steroid cholesterol is an important constituent of membranes; other steroids function as hormones. ? Differences between DNA and RNA DNA: The fundamental hereditary material of all living organisms. In eukaryotes, stored primarily in the cell nucleus.

A nucleic acid using deoxyribose rather than ribose. RNA: single stranded nucleic acid whose nucleotides use ribose rather than deoxyribose and in which the base uracil replaces thymine found in DNA. Serves as genome from some viruses. ? Surface area to volume ratios and the ability of cells to get nutrients in and waste products out of the cell ? Differences between prokaryotic and eukaryotic cells Prokaryotic: (single cell)The plasma membrane encloses the cell, regulating the traffic of materials into and out of the cell, and separating its interior from the external environment.

Eukaryotic: (multiple cells)Eukaryotic cells also contain other membrane-enclosed compartments in which specific chemical reactions occur. (Also refer to notes in manual and book pg 80-82) ? Know the functions of the various organelles, e.

g. , glyoxysomes, peroxisomes, ribosomes, chloroplasts, mitochondria, rough and smooth ER, Golgi, etc. Activity Manuel pg 39;40 ? What structures are unique to plants? ? Definition of chromatin Chromatin: The nucleic acid–protein complex that makes up eukaryotic chromosomes. ? DNA, nuclei, mitochondria, and chloroplasts Mitochondria: cells power plant

Chloroplast: An organelle bounded by a double membrane containing the enzymes and pigments that perform photosynthesis. Chloroplasts occur only in eukaryotes.

? Microtubules vs. microfilaments vs. intermediate filaments Microtubules: Tubular structures found in centrioles, spindle apparatus, cilia, flagella, and cytoskeleton of eukaryotic cells. These tubules play roles in the motion and maintenance of shape of eukaryotic cells. Microfilaments: In eukaryotic cells, a fibrous structure made up of actin monomers. Microfilaments play roles in the cytoskeleton, in cell movement, and in muscle contraction.

Intermediate filaments: Components of the ytoskeleton whose diameters fall between those of the larger microtubules and those of the smaller microfilaments. ? Simple diffusion vs. facilitated diffusion vs. osmosis vs. active transport Simple diffusion: molecule passes through membrane from a region of high to low concentration Facilitated diffusion: molecules passes through membrane from high to low concentration with the help of a protein Active transport: (energy input needed) relies on protein to go against concentration gradient Osmosis: Movement of water across a differentially permeable membrane, from one region to another region where the water potential is more negative. Hypertonic vs.

hypotonic vs. isotonic Hypertonic: Having a greater solute concentration. Water flows outside the cell. High to low concentration. Hypotonic: less solute in solution. Water flows in cell causing cell to swell.

Isotonic: same amount of solute in ; out of cell ? Symport vs. antiport, sodium-potassium pump Symport: A membrane transport protein that carries two substances in the same direction. Antiport: A membrane transport protein that moves one substance in one direction and another in the opposite direction Uniport: moves a single substance in one direction

Sodium-potassium pump: Antiporterresponsible for primary active transport; it pumps sodium ions out of the cell and potassium ions into the cell, both against their concentration gradients. Also called a sodium–potassium ATPase ? Endocytosis vs. exocytosis vs. pinocytosis vs.

receptor-mediated endocytosis Endocytosis: A process by which liquids or solid particles are taken up by a cell through invagination of the plasma membrane. Exocytosis: A process by which a vesicle within a cell fuses with the plasma membrane and releases its contents to the outside Pinocytosis: Endocytosis by a cell of liquid containing dissolved substances.

Receptor-mediated: Endocytosis initiated by macromolecular binding to a specific membrane receptor. ? Catabolism vs. anabolism Catabolism: (releases energy) pathways in which larger molecules are broken down into smaller ones Ex: cellular respiration Anabolism: (require energy) various pathways in which complex molecules are synthesized from simpler substances. Ex: protein synthesis ? Release of free energy and delta G values ? Properties of enzymes ? Competitive vs.

noncompetitive inhibitors Competitive: A nonsubstrate that binds to the active site of an enzyme and thereby inhibits binding of its substrate.

Noncompetitive inhibitors: A nonsubstrate that inhibits the activity of an enzyme by binding to a site other than its active site. How do enzymes speed up the rate of a reaction? ? Reversible vs. irreversible inhibition Reversible inhibition: Irreversible inhibition: ? Feedback inhibition ? Polar vs. nonpolar molecules and water solubility Nonpoler: Having electric charges that are evenly balanced from one end to the other Polar: Having separate and opposite electric charges at two ends, or poles.

Water solubility: ? Domains of life Archaea, bacteria, eukarya