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81 terms

Lecture Exam One Review

Fall 2011 Goudeau
STUDY
PLAY
Necessary Life Functions
maintaining boundaries, movement, responsiveness, digestion, metabolism, excretion, reproduction, growth
Metablolism
all reactions under way in the cells and tissues of the body at any given moment. Regulated by endocrine system.
Catabolism
Type of metabolism - a process in which complex substances are broken down into simpler substances (e.g., breakdown of tissue) Regulated by hormones secreted by endocrine system glands.
Anabolism
Type of metabolism - synthesis of more complex substances from simpler ones
Homeostasis
a tendency to maintain a balanced or constant internal state; the regulation of any aspect of body chemistry, such as blood glucose, around a particular level
Receptor
First component in maintaining homeostasis. Responds to stimuli by sending input to the Control Center
Control Center
Determines the set point - the level or range at which a variable is to be maintained.
Effector
Provides the means for the Control Center's response.
Afferent Pathway
information flows from the receptor along this pathway
Efferent Pathway
Pathway leaving the control center and going to the effector
Negative Feedback Mechanism
the output shuts off the original effect of the stimulus or reduces its intensity.
Positive Feedback Mechanism
FEEDBACK CONTROL SYSTEM THAT IS STIMULATORY; AMPLIFIES OR REINFORCES A CHANGE IN THE INTERNAL ENVIRONMENT
Four Tissue Types
Eipthelium, muscle, connective tissue, and nervous tissue
Organ Defined
Structure composed of at least two tissue types with a specific function.
Cells
Smallest units of living things
Which two systems regulate Homeostasis?
Nervous through neural impulses and endocrine through hormones.
Anatomy
study of body structure
Physiology
the branch of the biological sciences dealing with the functioning of organisms
What are the six levels of organization?
chemical-cellular-tissue-organ-organ systems-organism
What are the four major elements
CHON. "Chawn" Carbon, Hydrogen, Oxygen, Nitrogen. 96%
Isotopes
atoms of the same element that have different numbers of neutrons
Atomic Number
the number of protons in the nucleus of an atom
Atomic Mass
total mass of the protons and neutrons in an atom, measured in atomic mass units
Atomic Weight
average of the mass numbers of all isotopes
electron shells
an energy level representing the distance of an electron from the nucleus of an atom.
valence shell
The outermost energy shell of an atom, containing the valence electrons involved in the chemical reactions of that atom.
electron orbitals
volumes of space surrounding the atomic nucleus where electrons are likely to be found.
valence electrons
The electrons in the outermost shell (main energy level) of an atom; these are the electrons involved in forming bonds.
Ion
an atom or molecule that has gained or lost one or more electrons and has a negative or positive charge
Anion
A negatively charged atom due to the gain of one or more electrons.
Cation
an ion with a positive charge produced by the loss of one or more electrons
exergonic reaction
A spontaneous chemical reaction in which there is a net release of free energy.
endergonic reaction
A reaction where the product has more potential energy than the reactants. Anabolic reactions are endergonic.
enzymes
Proteins that allow certain chemical reactions to occur much faster than they would on their own.
phospholipid
A molecule that is a constituent of the inner bilayer of biological membranes, having a polar, hydrophilic head and a nonpolar, hydrophobic tail.
phospholipids
Modified triglycerides with a phosphorous containing group. Water loving head, water fearing tail.
Protein composition
made from amino acids (20 common types of amino acids) Long chain of amino acids joined by a peptide bond
Peptide bond
A bond that links amino acids together in a protein
Fibrous Protein
Protein that is extended and strandlike in shape. Help with structural framework (keratin, collagen.) Also help with movement by causing muscle cells to contract.
Globular Protein
spherical protein. plays crucial roles in virtually all biological processes " functional protiens" Proteins for enzymes, transport, body defense, regulation of pH, and metabolism.
Hydrolases
add water during hydrolysis reactions
Oxidases
enzymes that catalyze the transfer of oxygen
How does an enzyme speed up reactions?
Lowering the activation energy necessary for reaction
Plasma Membrane
The membrane at the boundary of every cell that acts as a selective barrier, thereby regulating the cell's chemical composition.
intracellular fluid
the cytoplasm found inside cells
extracellular fluid
fluid outside the cells
Smooth endoplasmic reticulum
no ribosomes are found on surface; contains collection of enzymes that perform special tasks that include the synthesis of membrane lipids and detoxification; the liver contains a lot of smooth er
Rough endoplasmic Reticulum
An endomembrane system covered with ribosomes where many proteins for transport are assembled.
cytosol
the aqueous part of the cytoplasm within which various particles and organelles are suspended
Mitochondrion
cell organelle that converts the chemical energy stored in food into compounds that are more convenient for the cell to use
Lysosome
filled with enzymes to breakdown dead cell parts and foreign objects; only found in animal cells
Centriole
one of two tiny structures located in the cytoplasm of animal cells near the nuclear envelope.
Peroxisome
organelle responsible for breaking down free radicals.
Golgi Apparatus
A system of membranes that modifies and packages proteins for export by the cell. The UPS of the cell
Ribosomes
small round structures that make proteins
Nucleolus
The organelle where ribosomes are made, synthesized and partially assembled, located in the nucleus
Chromatin
the readily stainable substance of a cell nucleus consisting of DNA and RNA and various proteins
Components of the Lipid Bilayer
Phosphate water-loving heads and fatty acid, water-fearing tales, cholesterol for structure, and glycolipids. Protein molecules are plugged into the outside or inside layers, or float around within.
Integral Proteins
Are firmly inserted into the bilayer. Some protrude from one side of the bilayer only, and others are transmembrane.
Function of Integral Proteins
Can act as channels through the membrane, or may act as carriers.
Peripheral Proteins
Protein appendages loosely bound to the surface of the membrane and not embedded in the lipid bilayer.
Functions of Membrane Proteins
1. cell to cell communication
2. transport
3. intercellular joining
Osmosis
The diffusion of a solvent, such as water, through a selectively permeable membrane. Osmosis occurs until the Osmotic Pressure and Hydrostatic Pressure equal out.
Active Transport
Transfers taking place agains the concentration gradient and requiring energy.
Passive Transport
The movement of materials through a cell membrane without using energy. Transfers with the flow of the concentration gradient
Diffusion
process by which molecules tend to move from an area where they are more concentrated to an area where they are less concentrated
Simple diffusion
Nonpolar lipid-soluble (hydrophobic) substances diffuse directly through the phospholipid bilayer
Facilitated Diffusion
Passive transport of molecules through the membrane employing a protein channel or a carrier.
Aquaporins
Water channel proteins that allow water to pass right through them. They keep water away from the hydrophobic tails during transport
Leakage Channels
channels that are always open
Gated Channels
A protein channel in a cell membrane that opens or closes in response to a particular stimulus.
Osmolarity
The measure of total concentration of solute particles.
When solutions of different osmolarity are separated by a membrane, osmosis occurs until equilibrium is reached
Isotonic Solutions
Same solute/water concentration on inside and outside of cell. Water moves in and out. Cell is normal size.
Hypertonic Solutions
Higher concentration of solutes in the interstitial fluid. Pulls water from cells, causing them to shrink (crenation)
Hypotonic Solutions
Lower concentration of solutes in the interstitial fluid. Water flows into the cell causing it to swell (possibly burst.)
Tonicity
The ability of a solution to cause a cell within it to gain or lose water. Tonicity is telling us about the solute concentration of a fluid.
Hydrostatic Pressure
The force exerted on a membrane by water.
Osmotic Pressure
The tendency of water to move into the cell by osmosis
Exocytosis
process by which a cell releases large amounts of material
Endocytosis
process by which a cell takes material into the cell by infolding of the cell membrane
Vesicular Transport
Fluids containing large particles and macromolecules are transported across cellular membranes inside membranous sacs called vesicles. (ex: exocytosis and endocytosis.)