Necessary Life Functions
maintaining boundaries, movement, responsiveness, digestion, metabolism, excretion, reproduction, growth
all reactions under way in the cells and tissues of the body at any given moment. Regulated by endocrine system.
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.
Type of metabolism - synthesis of more complex substances from simpler ones
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
First component in maintaining homeostasis. Responds to stimuli by sending input to the Control Center
Determines the set point - the level or range at which a variable is to be maintained.
Provides the means for the Control Center's response.
information flows from the receptor along this 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
Structure composed of at least two tissue types with a specific function.
Smallest units of living things
Which two systems regulate Homeostasis?
Nervous through neural impulses and endocrine through hormones.
study of body structure
the branch of the biological sciences dealing with the functioning of organisms
What are the six levels of organization?
What are the four major elements
CHON. "Chawn" Carbon, Hydrogen, Oxygen, Nitrogen. 96%
atoms of the same element that have different numbers of neutrons
the number of protons in the nucleus of an atom
total mass of the protons and neutrons in an atom, measured in atomic mass units
average of the mass numbers of all isotopes
an energy level representing the distance of an electron from the nucleus of an atom.
The outermost energy shell of an atom, containing the valence electrons involved in the chemical reactions of that atom.
volumes of space surrounding the atomic nucleus where electrons are likely to be found.
The electrons in the outermost shell (main energy level) of an atom; these are the electrons involved in forming bonds.
an atom or molecule that has gained or lost one or more electrons and has a negative or positive charge
A negatively charged atom due to the gain of one or more electrons.
an ion with a positive charge produced by the loss of one or more electrons
A spontaneous chemical reaction in which there is a net release of free energy.
A reaction where the product has more potential energy than the reactants. Anabolic reactions are endergonic.
Proteins that allow certain chemical reactions to occur much faster than they would on their own.
A molecule that is a constituent of the inner bilayer of biological membranes, having a polar, hydrophilic head and a nonpolar, hydrophobic tail.
Modified triglycerides with a phosphorous containing group. Water loving head, water fearing tail.
made from amino acids (20 common types of amino acids) Long chain of amino acids joined by a peptide bond
A bond that links amino acids together in a 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.
spherical protein. plays crucial roles in virtually all biological processes " functional protiens" Proteins for enzymes, transport, body defense, regulation of pH, and metabolism.
add water during hydrolysis reactions
enzymes that catalyze the transfer of oxygen
How does an enzyme speed up reactions?
Lowering the activation energy necessary for reaction
The membrane at the boundary of every cell that acts as a selective barrier, thereby regulating the cell's chemical composition.
the cytoplasm found inside cells
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.
the aqueous part of the cytoplasm within which various particles and organelles are suspended
cell organelle that converts the chemical energy stored in food into compounds that are more convenient for the cell to use
filled with enzymes to breakdown dead cell parts and foreign objects; only found in animal cells
one of two tiny structures located in the cytoplasm of animal cells near the nuclear envelope.
organelle responsible for breaking down free radicals.
A system of membranes that modifies and packages proteins for export by the cell. The UPS of the cell
small round structures that make proteins
The organelle where ribosomes are made, synthesized and partially assembled, located in the nucleus
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.
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.
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
3. intercellular joining
The diffusion of a solvent, such as water, through a selectively permeable membrane. Osmosis occurs until the Osmotic Pressure and Hydrostatic Pressure equal out.
Transfers taking place agains the concentration gradient and requiring energy.
The movement of materials through a cell membrane without using energy. Transfers with the flow of the concentration gradient
process by which molecules tend to move from an area where they are more concentrated to an area where they are less concentrated
Nonpolar lipid-soluble (hydrophobic) substances diffuse directly through the phospholipid bilayer
Passive transport of molecules through the membrane employing a protein channel or a carrier.
Water channel proteins that allow water to pass right through them. They keep water away from the hydrophobic tails during transport
channels that are always open
A protein channel in a cell membrane that opens or closes in response to a particular stimulus.
The measure of total concentration of solute particles.
When solutions of different osmolarity are separated by a membrane, osmosis occurs until equilibrium is reached
Same solute/water concentration on inside and outside of cell. Water moves in and out. Cell is normal size.
Higher concentration of solutes in the interstitial fluid. Pulls water from cells, causing them to shrink (crenation)
Lower concentration of solutes in the interstitial fluid. Water flows into the cell causing it to swell (possibly burst.)
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.
The force exerted on a membrane by water.
The tendency of water to move into the cell by osmosis
process by which a cell releases large amounts of material
process by which a cell takes material into the cell by infolding of the cell membrane
Fluids containing large particles and macromolecules are transported across cellular membranes inside membranous sacs called vesicles. (ex: exocytosis and endocytosis.)