BSC 181 1st EditionExam # 1 Study Guide- All body functions are spread among the different organ systems. All of which cooperate and work together to keep the cells functioning and alive.- Receptor- (sensor) monitors environment, senses change, responds to stimuli- Control Center- receives input from receptor, determines appropriate response.- Effector- receives output from control center, provides means to respond, response either reduces (negative feedback) or enhances (positive feedback) stimulus. Some structures that can be an effector are muscles (smooth, cardiac, and skeletal) and glands.- Negative feedback- (most common) response either reduces or shuts off original stimulus; variable changes in opposite direction of initial change.- Positive feedback- cascade or amplifying effect; response enhances or exaggerates original stimulus.Anatomical Positioning:- Axial- head, neck, trunk- Appendicular- limbs- Saggital- Divides body vertically into right and left parts- Frontal (coronal)- Divides body vertically into anterior and posterior parts- Transverse (horizontal)- Divides body horizontally (90° to vertical plane) into superior and inferior parts- Dorsal Body Cavity (back)- cranial and vertebral cavity- Ventral Body Cavity (front)- houses internal organs-Thoracic cavity- lungs, merdiastinum, pericardial - Abdominopelvic cavity- -abdominal- stomach, intestines, spleen, liver-pelvic- bladder, reproductive organs, rectumAtomic Structures:- Nucleus- almost entire mass of atom, contains protons and neutrons- Protons- positive charge, 1 amu- Neutron- no charge, 1 amu- Electron- negative charge, same amount in atom as protons, in orbitals in electron cloud, 1/2000 mass of a proton- Valence shell- outermost electron shell, most potential energy, most chemically reactive- Atomic weight- average mass numbers of all isotopes of an atom- Atomic mass- total number of protons and neutrons- Atomic number- number of protons- Ions- atom gains or loses electrons and becomes charged, number of protons stays the same (anion if negative, cation if positive)- The different between and ion and an isotope: in an ion the number of electrons changes, in an isotope the number of neutrons changesMixtures:- Solutions- homogeneous mixtures. Has a solvent (usually liquid, substance present in greatest amount) and a solute (present in smaller amounts)- Colloids- substance microscopically dispersed evenly throughout another substance (heterogeneous)- Suspension- large, visible solutes, settle out (heterogeneous)Chemical Bonds and Reactions:- Ionic- atom gains or loses electrons and becomes charged, opposite charges react- Covalent- formed by sharing of two or more valence shell electrons, allows each atom to fill its valence shell at least part of the time - Hydrogen- (not a true bond) attractive force between electropositive atom of another molecule- Octet rule- (rule of eights) except for the first shell (full with two electrons) atomsinteract to have eight electrons in their valence shell- Polar- unequal sharing of electrons (like H2O)- Nonpolar- electrons shared equally- Synthesis (combination) reactions- A+BAB; atoms/ molecules combine to form alarger, more complex molecule; anabolic- Decomposition reaction- ABA+B, molecule is broken down into smaller molecules or its constituent atoms, catabolic- Exchange reactions- AB+CAC+B, bonds are made and bonds are broken- When the temperature rises, the rate of chemical reaction rises- When the concentration of a reactant rises, the rate of the chemical reaction rises- When the particle size goes down, the rate rises- Catalysts speed up the rate of the chemical reaction without being chemically changed or involved in the product (example: enzymes)Compounds- Organic compounds- (carbohydrates, lipids, proteins, nucleic acids) contain carbon and are covalently bonded- Inorganic compounds- (water, salts, many acids, many bases) do not contain carbon- Organic and inorganic compounds are equally essential- Organic compound 4 categoriesCarbohydrates- major source of cellular fuelLipids- energy storage, insulation, protectionProteins- made of amino acidsNucleic acid- largest molecule in the bodypH scale- Ranges from 0-14- Higher acidity= lower pH number- pH= -log(H+ in moles per liter)Proteins:- Primary structure- order in which amino acids are arranged (peptide bondsconnect one amino acid to the next)- Secondary structure- shapes that the polypeptide chain takes (coiled/helix orpleated/sheet)- Tertiary structure- three-dimensional shape that the pleats or coils take- Quarternary structure- combination of two or more tertiary proteins, not allproteins will reach this stage- Fibrous (structural)- strandlike, water-insoluble, stable, most are tertiary orquaternary, provide mechanical support and tensile strength (example: collagen,single most common protein in the body)- Globular (functional)- compact, speherical, water soluble, sensitive toenvironmental changes, specific functional regions (example: antibodies,hormones, enzymes)- Enzymes= globular proteins that act as biological catalysts, lower activation rateand increase the speed of a chemical reactionDNA and RNADNA RNADouble-stranded Single-strandedBases= Adenine, Guanine, Cytosine, andThymineBases= Adenine, Guanine, Cytosine, andUracilIn the nucleus Outside nucleus- Codon- the three-base sequence on a messenger RNA molecule that provides thegenetic information used in protein synthesis; code for a given amino acid- 3 types of RNA:-Messenger (mRNA)- carries the genetic information from DNA in the nucleus to the ribosomes in the cytoplasm-Transfer (tRNA)- bound to amino acids base pair withthe codons of mRNA at the ribosome to begin the process of protein synthesis-Ribosomal (rRNA)- structural component of ribosomes- ATP- chemical energy in glucose, directly powers chemical reactions in cells,immediately usableOrganelles:- Mitochondria- provide most of the cells ATP via aerobic- Ribosomes- site of protein synthesis- Endoplasmic reticulum-Smooth- catalyzes reactions in liver and testesRough- manufactures all secreted proteins- Golgi apparatus- packages proteins, moves to designated parts around the cell- Lysosomes- digest ingested