Bio Ch 4 - Cells Membranes & Environments Flashcards
Active Transport
Movement of molecules across a cell membrane from Low concentration to High concentration
Difusion
The spreading of a substance from region of high concentration to a region of low conctration
Extracellular Fluid
All body fluids outside the cells.
E.g. blood plamsa, cranial fluid. In Humans about 33% of the total fluid
partially permeable
Something that will allow only certain molecules or ions to pass through it
Solute
Substance that is disolved in a solvent
e.g. salt in sea water
Cell Membrane
**Eukaryote **cells = **
- Plasma Membrane
- Interconnected network of membranes inside the cell
Prokaryote (bacteria cells) =
- plasma membrane only
Endocytosis
Process by which cells absorb molecules by engulfing them
(Energy using process required because proteins etc can’t move through the cell wall.)
Facilitated diffusion
Process of spontaneous passive transport of molecules/ions across a cell membrane.
(Different to Active Transport, and uses specific protein gateways)
Osmosis
Spontaneous movement of solvent through a semipermeable membrane into a region of higher solute concentraion in a way that equalises the solute concentrations
i.e. Movement of Water from low salt solution into the egg (when it has more salt)
Phospholipids
Class of Lipids that make up cell membranes
Can form lipid bilayers
Solvent
A substance that disolves a solute
e.g. Water in sea water
Cholesterol
Orgainic molecule which is essential structural part of cell wall
Cholesterol enables animal cells to
- not need a cell wall (like plants & bacteria) to protect membrane integrity/cell-viability and thus be able to
- change shape and
- move about (unlike bacteria and plant cells which are restricted by their cell walls).
Exocytosis
Process by which cells excrete molecules by extruding them.
Consumes energy and is different to diffusion methods
Fluid-Mosaic Model
Describes Cell Membranes
Double layer of molecules form ‘blanket’ that can move around (fluidity) with scattered proteins (mosaic). Specific carbohydrates attach which allow cells to link to/recognize one another.
Osmotic Gradient
Difference in concentration between two solutions on either side of a semipermeable membrane
Plasma Membrane
Membrane that encloses the cytoplasm
Surface Area to Volume Ratio
Surface area divided by volume – sa/vol Function of the shape of the cell
Organ structure can be to increase sa/vol:
- Lungs (branching and alveoli)
- Intestine (wrinkles – called villi)
Increased surface area causes problems
- Loss of water
- Temperature control
Individual cells can also be shaped to increase sa/vol
Concentration Gradient
Difference between solute concentrations
External Environment
The fluid in which an organism lives
Unicellular organisms can either
- Tolerate conditions
- Move (slowly) to better conditions
- Die
Internal Environment
Multicellular organisms maintain an internal environment for cells inside their skin. Makes cell function more efficient
Osmotic Pressure
The pressure causing the water to move through an osmotic membrane
Ratio
X divided by Y
X:Y
Turgid
Plant cells with high internal fluid pressures
- Plant cell take in water to the point where the cellulose cell walls stop expanding futher.
- Animal cells will keep swelling until they burst.
active site
the part of an enzyme that interacts with the substrate duringcatalysis.
aerobic
pertaining to or caused by the presence of oxygen.
anaerobic
pertaining to or caused by the absence of oxygen.
ADP
Also called adenosine diphosphate,adenosinediphosphoric acid. Biochemistry. anester of adenosine and pyrophosphoric acid, C 10 H12 N 5 O 3 H 3 P 2 O 7, derived from ATP, andserving to transfer energy during glycolysis.
ATP
Biochemistry. adenosine triphosphate: an ester ofadenosine and triphosphoric acid, C 10 H 12 N 5 O 4H 4 P 3 O 9, formed especially aerobically by thereaction of ADP and an orthophosphate duringoxidation, or by the interaction of ADP andphosphocreatine or certain other substrates, andserving as a source of energy for physiologicalreactions, especially muscle contraction.
catalyst
a substance that causes or acceleratesa chemical reaction without itself being affected.
cellular respiration
the oxidation of organic compounds that occurswithin cells, producing energy for cellularprocesses.
chemical energy
Energy liberated by a chemical reaction or absorbed inthe formation of a chemical compound.
chlorophyll
the green coloring matter of leaves and plants,essential to the production of carbohydrates byphotosynthesis,
chloroplast
a plastid containing chlorophyll.
coenzyme
a molecule that provides the transfer site forbiochemical reactions catalyzed by an enzyme.
Animalia
the kingdom comprising all animals.
cell
a usually microscopic structure containingnuclear and cytoplasmic material enclosed by asemipermeable membrane and, in plants, a cellwall; the basic structural unit of all organisms.
cell mebrane
the semipermeable membrane enclosing thecytoplasm of a cell.
Cell theoy
- All living things are made up of cells.
- Cells are the basic units of structure and function in living things.
- Living cells come only from other living cells.
cell wall
the definite boundary or wall that is part of theouter structure of certain cells, as a plant cell.
centriole
a small, cylindrical cell organelle, seen near thenucleus in the cytoplasm of most eukaryotic cells,that divides in perpendicular fashion duringmitosis, the new pair of centrioles moving ahead ofthe spindle to opposite poles of the cell as the celldivides: identical in internal structure to a basalbody.
Cilia
minute hairlike organelles, identical instructure to flagella, that line the surfaces ofcertain cells and beat in rhythmic waves, providinglocomotion to ciliate protozoans and moving liquidsalong internal epithelial tissue in animals.
cytosol
the water-soluble components of cell cytoplasm,constituting the fluid portion that remains afterremoval of the organelles and other intracellularstructures.
endoplasmic reticulum
a network of tubular membranes within thecytoplasm of the cell, occurring either with asmooth surface (smooth endoplasmicreticulum) or studded with ribosomes (roughendoplasmic reticulum) involved in thetransport of materials.
eukaryote
a membrane-bound nucleus
flagella
a long, lashlike appendage serving as anorgan of locomotion in protozoa, sperm cells, etc.
Golgi apparatus
an organelle, consisting of layers of flattened sacs,that takes up and processes secretory andsynthetic products from the endoplasmic reticulumand then either releases the finished products intovarious parts of the cell cytoplasm or secretesthem to the outside of the cell.
heterotroph
an organism requiring organic compoundsfor its principal source of food.
lysosome
a cell organelle containing enzymes that digestparticles and that disintegrate the cell after itsdeath.
mitochondrion
an organelle in the cytoplasm of cells thatfunctions in energy production.
Monera
a taxonomic kingdom of prokaryotic organismsthat typically reproduce by asexual budding orfission and have a nutritional mode of absorption,photosynthesis, or chemosynthesis, comprising thebacteria, blue-green algae, and various primitivepathogens.
nucleoid
the central region in a prokaryotic cell, as abacterium, that contains the chromosomes andthat has no surrounding membrane.
nucleus
found in most living eukaryotic cells, directing theirgrowth, metabolism, and reproduction, andfunctioning in the transmission of genic characters.
ribosome
a tiny, somewhat mitten-shaped organelleoccurring in great numbers in the cell cytoplasmeither freely, in small clusters, or attached to theouter surfaces of endoplasmic reticula, andfunctioning as the site of protein manufacture.
Plantae
the taxonomic kingdom comprising all plants.
plastid
a small, double-membraned organelle of plant cellsand certain protists, occurring in several varieties,as the chloroplast, and containing ribosomes,prokaryotic DNA, and, often, pigment.
Protista
a taxonomic kingdom comprising the protists.
synchrotron
a type of cyclotron consisting of magnetic sectionsalternately spaced with sections in which particles areelectrostatically accelerated.
tonoplast
a membrane separating a vacuole from the surroundingcytoplasm in a plant cell.
vacuole
a membrane-bound cavity within a cell, often containing awatery liquid or secretion.
virion
the infectious form of a virus as it exists outside the hostcell, consisting of a nucleic acid core, a protein coat, and,in some species, an external envelope.
endoplasmic reticulum
a network of tubular membranes within the cytoplasm ofthe cell, occurring either with a smooth surface (smoothendoplasmic reticulum) or studded with ribosomes(rough endoplasmic reticulum) involved in thetransport of materials.
enzyme
any of various proteins, as pepsin, originating from livingcells and capable of producing certain chemical changes inorganic substances by catalytic action, as in digestion.
denaturation
to treat (a protein or the like) by chemical orphysical means so as to alter its original state.
fermentation
a change brought about by a ferment, as yeast enzymes,which convert grape sugar into ethyl alcohol.
glycolysis
the catabolism of carbohydrates, as glucose and glycogen,by enzymes, with the release of energy and the productionof lactic or pyruvic acid.
Golgi apparatus
an organelle, consisting of layers of flattened sacs, thattakes up and processes secretory and synthetic productsfrom the endoplasmic reticulum and then either releasesthe finished products into various parts of the cellcytoplasm or secretes them to the outside of the cell.
lysosome
a cell organelle containing enzymes that digest particlesand that disintegrate the cell after its death.
mitochondrion
an organelle in the cytoplasm of cells that functions in energy production.
nucleus
a specialized, usually spherical mass ofprotoplasm encased in a double membrane, and found inmost living eukaryotic cells, directing their growth,metabolism, and reproduction, and functioning in thetransmission of genic characters.
organic
characteristic of, pertaining to, or derived from livingorganisms :
photosynthesis
the complex process by which carbon dioxide, water, andcertain inorganic salts are converted into carbohydrates bygreen plants, algae, and certain bacteria, using energyfrom the sun and chlorophyll.
protein
a substance thought to be the essentialnitrogenous component of all organic bodies.
ribosome
a tiny, somewhat mitten-shaped organelle occurring ingreat numbers in the cell cytoplasm either freely, in smallclusters, or attached to the outer surfaces of endoplasmicreticula, and functioning as the site of proteinmanufacture.
RNA
ribonucleic acid: any of a class of single-strandedmolecules transcribed from DNA in the cell nucleus or inthe mitochondrion or chloroplast, containing along thestrand a linear sequence of nucleotide bases that iscomplementary to the DNA strand from which it istranscribed: the composition of the RNA molecule isidentical with that of DNA except for the substitution of thesugar ribose for deoxyribose and the substitution of thenucleotide base uracil for thymine.
substrate
the substance acted upon by an enzyme.
adaptation
any alteration in the structure or function of anorganism or any of its parts that results from naturalselection and by which the organism becomes betterfitted to survive and multiply in its environment.
a form or structure modified to fit a changedenvironment.
the ability of a species to survive in a particularecological niche, especially because of alterations ofform or behavior brought about through naturalselection.
amino acid
any of a class of organic compounds that contains at leastone amino group, –NH 2, and one carboxyl group, –COOH:the alpha-amino acids, RCH(NH 2)COOH, are the buildingblocks from which proteins are constructed.
carbohydrate
any of a class of organic compounds that are polyhydroxyaldehydes or polyhydroxy ketones, or change to suchsubstances on simple chemical transformations, ashydrolysis, oxidation, or reduction, and that form thesupporting tissues of plants and are important food foranimals and people.
control group
a group of subjectsclosely resembling the treatment group in manydemographic variables but not receiving the activemedication or factor under study and thereby serving as acomparison group when treatment results are evaluated.
controlled experiment
an experiment or trial that uses controls, usuallyseparating the subjects into one or more control groupsand experimental groups.
dependent variable
the variable measured
experimental group
a group of subjects whoare exposed to the variable under study:
hypothesis
a proposition, or set of propositions, set forth as anexplanation for the occurrence of some specified group ofphenomena, either asserted merely as a provisionalconjecture to guide investigation
independent variable
the variable change or manipulated
lipid
fatty acid
natural selection
the process by which forms of life having traits that betterenable them to adapt to specific environmental pressures,
nitrogen fixation
this process as performed by certain bacteria found in thenodules of leguminous plants, which make the resultingnitrogenous compounds available to their host plants.
nucleic acid
any of a group of long, linear macromolecules, either DNAor various types of RNA, that carry genetic informationdirecting all cellular functions: composed of linkednucleotides.
organic compound
A compound containing hydrocarbon groups.
organism
a form of life considered as an entity; an animal, plant,fungus, protistan, or moneran.
phylogeny
the development or evolution of a particular group oforganisms.
principle
a fundamental, primary, or general law or truth from whichothers are derived:
scientific method
a method of research in which a problem is identified,relevant data are gathered, a hypothesis is formulatedfrom these data, and the hypothesis is empirically tested.
surface tension
the elasticlike force existing in the surface of a body,especially a liquid, eg water
theory
contemplation or speculation:
or
a coherent group of tested general propositions, commonlyregarded as correct, that can be used as principles ofexplanation and prediction for a class of phenomena: Einstein's theory of relativity.
