Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
74 Cards in this Set
- Front
- Back
Cell
|
Basic, living structural and functional unit of the body
|
|
Cytology
|
the study of cells
|
|
Plasma Membrane
|
Outer membrane which seperates the cells internal and external environments
|
|
Cytosol
|
The thick semifluid portion of the cytoplasm.
Contains: soluble proteins & enzymes, nutrients, ions, and organelles |
|
Cytoplasm
|
All the cell contents between the plasma membrane and nucleus
|
|
Organelles
|
Distinct structures with specific functions
|
|
Inclusions
|
Temporary structures that contain secretions and storage products of the cell
|
|
Fluid Mosaic Model
|
Plasma membrane is a fluid lipid bilayer with proteins embedded in it. This is the most current model. (Lock and Key" model isn't used anymore but still a decent model)
|
|
Microtubules
|
Protein tubulin, 25nm in diameter, causes entire movement of cell
|
|
Function of Glycolipids
|
Not completely known; allows adhesions among cells and tissues; mediates cell to cell recignition & communication; helps regulate growth & development
|
|
Ampipathic
|
Has polar and non-polar
|
|
Plasmalemma structure
|
-Bilayer of lipids embedded w/ proteins
-Lipid bilayer makes the membrane semi-permeable allowing only nonpolar, non-ionized substances easy entrence into the cell -Embedded proteins act as channels, receptors, or makers -Polar heads = Hydrophilic -Nonpolar tails = Hydrophobic -Phospholipids have a nonpolar region and a polar region making them ampipathic -75% of lipids of the cell membranes are phospholipids 5% of membrane lipids are glycolipids appearing only in layer facing extracellular fluid |
|
Cholesterol & Cell Membrane
|
-About 20% of membrane lipids are cholesterol
-Found on both sides of bilayer -Function is to strengthen membrane but also to allow flexibility |
|
Membrane structure proteins
|
Includes integral & peripheral proteins
|
|
Integral proteins
|
-Extends across the bilipid layer; mostly glycoproteins
-Functions are: channels, transporters, receptors, enzymes, cell identity makers (blood maker) |
|
Major hystocompatability complex (MHC)
|
Is a surface protein
(Immune system recognizes "self" from "non-self" |
|
Peripheral proteins
|
-Don't extend across the bilayer
-Loosely attached to the inner & outer surfaces -Functions include: enzymes, cytoskeleton anchors (attaching plasmalemma & cytoskeleton filamins) |
|
Membrane Physiology
|
-Provides communication
-Allows electrochemical gradient. (Chemical ion difference: Extracellular fluid contains Na+ & Cl-, intracellular contains K+ and PO4- and negatively charged amino acids) -Electrical gradient exists because the inside surface is more negatively charged than outside. Creates membrane potential (a voltage across membrane) |
|
Membrane potential
|
-Occurs when pos and neg charges are separated
-Voltage = potential energy |
|
Electrical Gradient
|
-Overall, the cell and extracellular fluid is neutral (balance in pos and neg charges)
-The voltage of cells throughout your body is normally -20mV to -200mV. (negative means inside of cell is more neg to outside) |
|
Sodium/Potassium Pump (Na/K Pump)
|
3:2 ratio (3 Na to 2 K ratio)
-For more info, refer to Electrical Gradient flashcard |
|
Selectively Permeable
|
4 Factors influence permeability
-Lipid solubility -Size (large molecules can't pass through) -Charge (Membrane is impermeable to all charged molecules and ions; they can still pass through channels) -Presense of channels and transporters (proteins allow permeability of certain polar and charged substances that cannot pass through lipid bilayer) |
|
Movemend of Materials Across Membrane
|
2 types of processes:
-Passive (doesn't require cellular energy such as simple diffusion, Osmosis, Filtration, Ficilitated diffusion, Dialysis) -Active |
|
Simple diffusion
|
Movement from areas of high to low concentration
-A concentration gradient forms when a substance is present in high amounds in one area and low amounts in another -Net diffusion is the difference in diffusion between 2 areas -Equilibrium is reached after a period of time -Diffusion in the human body occurs with H2O, O, CO2, N, Steroids, etc. -H2O diffuses via imperfections of the cell -H2O filled channels alsow allow diffusion of Na+, K+, Ca+, Cl-, and HCO3 |
|
Passive Processes - Osmosis
|
Net movement of a solvent (water) from areas of high water concentration to areas of low concentration (Condensation)
-Direction of flow of water into/out of cells depends on Tonicity (Isotonic, Hypotonic, Hypertonic |
|
Isotonic
|
balance of solution in two sealed areas
|
|
Hypotonic
|
Less solid, more water in a solution
|
|
Hypertonic
|
More solid, less water in a solution
|
|
Passive Transport - Filtration
|
-In filtration, water (solvent) and some dissolved substances (solute) move across a membrane due to gravity or water pressure (Hydrostatic pressure - the force of a fluid pushing against surface)
-Movement occurs from high hydrostatic pressure to low hydrostatic pressure -Filtration occurs in our kidneys (blood forces water and small molecules through the membranes of the cell lining the capilaries - the filtered liquid then enters the kidneys) -Dialysis is driven by concentration gradient while filtration is driven by hydrostatic pressure gradient |
|
Passive Transport - Facilitated Diffusion
|
-Some substances are too large to pass through the plasma membranes, but can with the help of integral transports called transporters
-Glucose enters the cell this way |
|
Passive Transport - Dialysis
|
-Dialysis is the diffusion of small solutes but not large ones through a selectively permeable membrane
|
|
Active processes
|
Active processes mechanisms require cellular energy
-Move substances against a concentration gradient -Include: Active transport (sodium pump, symports & antiports), and Bulk transport (endocytosis, phagocytosis, pinocytosis, receptor - mediated endocytosis, and exocytosis) |
|
Active Transport
|
-Primary active transport - Sodium pump; maintains a low concentration of sodium ions in the cytosol by pumping them out against their concentration gradient; also moves K+ pump ions in; the pump is a protein
-Secondary active transport (symports & antiports) --Symports allow glucose and amino acids to enter the cell; the return nutrients to the blood that were filtered out by the kidneys --Antiports keep Ca+ concentration ions low in the cytosol; helps regulate pH |
|
Bulk transport - Endocytosis
|
-Phagocytosis (cell eating) example: membrane engulfs droplet to eat
-Pinocytosis (cell drinking) example: oocyte drinks liquids in uterus -Receptor mediated endocytosis |
|
Bulk transport - Exocytosis
|
-Secretory vesicles form and secrete contents
-Important in nerve cells as they release neurotransmitters and in secretory cells that release digestive enzymes or hormones such as insulin |
|
Achromatopsia
|
Complete lack of color vision, can be caused by damage to the Thalamus or Cerebral Cortex (damage is sometimes caused by a brain tumor)
|
|
Cytosol contains:
|
Water and solid components such as proteins, lipids, carbs, and inorganic substances
|
|
Nucleus (the control center)
|
-Surrounded by nuclear envelope
-Has 1 more nucleoli (aggregates of DNA, RNA and proteins which assemble ribosomes) -Chromatin is DNA in a nondividing cell -Chromosomes is during cell division, chromatin condences into chromosomes -Histones are proteins around which DNA wraps |
|
Nucleus contains:
|
Genes, controls metabolic activities, dictates protein synthesis, nuclear pores which allows ions and water soluble substances entrance into the cell
(DNA never leaves the nucleus) |
|
RNA stands for...
|
Ribonucleic Acid
|
|
3 types of RNA
|
mRNA - messenger
tRNA - transfer rRNA - rebosomal |
|
When and by whom was the Nucleus first described?
|
In 1831 by Robert Brown
|
|
Nucleolus is made of...
|
Nucleolus = made of RNA; it's job is to synthesize rRNA
|
|
mRNA
|
Messenger RNA
|
|
tRNA
|
Transfer RNA
|
|
rRNA
|
Ribosomal RNA
|
|
Chromatin vs. Chromosomes
|
Chromatin - Non-dividing
Chromosomes - Dividing (gametes don't have chromosomes) |
|
Organelles - Endoplasmic Reticulum (ER)
|
2 types: Rough and Smooth (RER and SER) and are both membranes.
Means "within the cytoplasm" and "a little net" |
|
Rough Endoplasmic Reticulum (RER)
|
-Contains ribosomes
-This is where protein synthesis occurs -Proteins are made in the ribosomes then move through ER to the Golgi Complex -Free ribosomes make proteins for the cells own use |
|
Smooth Endoplasmic Reticulum (SER)
|
-Lacks Ribosomes
-Contains enzymes that synthesize carbs and lipids |
|
Ribosomes make...
|
Ribosomes make Proteins
|
|
SER Lipids
|
Cholesterol - lipid
Testosterone - lipid Estragen - lipid |
|
RER lipids
|
Antibody - protein
Insulin - protein Actin - protein Myosin - protein Collagen - protein Keratin - protein |
|
The cells of the testes have extensive amounds of SER?
True or False? |
True
The testes make Testosterone |
|
Golgi Complex
|
-Is membranous
-Made of cisternae -Modifies, packages, exports proteins (through secretory vesicles) -Forms glycoproteins or glycolipids |
|
Another term for Oxidative metabolism
|
Cellular Respiration
|
|
Lysosomes
|
-Membranous
-Contains digestive enzymes -Called "digestive bags" or "cellular garbage bags" Example: WBC's contain lysosomes; Tay-Sachs occurs because of improperly functioning lysosomes (WBC's phagocytize [or eat] bacteria) |
|
Peroxisomes
|
-Membranous
-Detoxes harmful substances -Found in kidney and liver cells -Contain the enzymes peroxidase and catalase to break down H2O2 |
|
Mitochondria
|
-Powerplants
-Cristae "inner membrane" which contains enzymes -Infolding increases surface area -Cellular respiration occurs here (forms ATP) -Endosymbiont theory -Exercise increases number and size of mitochondria |
|
ATP
|
Adenosine Triphosphate
|
|
ADP
|
Adenosine Diphosphate
|
|
Adenosine Diphosphate + Phosphate = ?
(ADP + P = ?) |
(ADP + P = ATP)
|
|
Cytoskeleton
|
Internal supporting framework of the cell
3 types of cell fibers that make up the cytoskeleton -Microfilaments -Intermediate filaments -Microtubules |
|
Microfilaments
|
-7nm
-Looks like strands of twisted beads -Example: The protein Actin is found in skeleton muscle for contraction |
|
Intermediate filaments
|
-10nm
-For support -Example: The protein Keratin in the skin is made of this |
|
Microtubules
|
-25nm
-"engines" of cell because they move things around -Causes entire movement of cell -Centrosome (Microtubule organizing center; important for cell division; forms microtubules necessary for cell division; made of a pair of centrioles) -Example: Protein tubulin |
|
Cell Extensions (things extending from the outer cell
|
3 types
-Microvilli -Cilia -Flagella |
|
Microvilli
|
-Fingerlike
-Epithelial of intestine -is for absorbsion, increases surface area |
|
Cilia
|
-Short hair-like
-Made of 9+2 microtubular arrangement -Found in respiratory tract and female reproductive tract |
|
Flagella
|
-Long whip-like tail
-Made of 9+2 microtubule arrangement -Found only on sperm cells in humans |
|
Cell connections
|
-Integrins (proteins that holds cells in place in a tissue
-Selectin, cadherins, immunoglobulins (proteins that form cell-to-cell connections Types of connections: Desmosomes, Gap junctions, Tight junctions |
|
Desmosomes
|
-Fibers interlock like velcro
-Holds adjacent cells together -Internally anchored by intermediate filaments -Example: Skin cells |
|
Gap Junctions
|
-Form tunnels between 2 cells so materials or electrical impulses may directly pass through
-Example: Heart muscle cells |
|
Tight Junctions
|
-Binds adjacent cells like plastic collars on 6-packs
-Prevents leaks -Example: Bladder or intestinal lining |