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;
78 Cards in this Set
- Front
- Back
The cellular level of organization
|
basic, living, structural and functional unit of the body
|
|
The cellular level of organization is responsible for
|
-compartmentalization of chemical reactions within specialized structures
-regulate inflow and outflow of materials -use genetic material to direct cell activities |
|
cytology
|
study of cellular structure
|
|
cell physiology
|
study of cellular function
|
|
plasma membrane
|
cell membrane
|
|
nucleus
|
genetic material of cell
|
|
cytoplasm
|
everything between the membrain and the nucleus
|
|
what is found between the membrane and nucleus?
|
cytosol
organelles |
|
cytosol
|
intracellular fluid
|
|
organelles
|
subcellular structures with specific functions
|
|
plasma membrane
|
held together by hydrogen bonds
|
|
lipid bilayer of the cell membrane
|
2 back to back layers of 3 types of lipid molecules.
cholesterol and glycolipids scattered among a double row of phospholipid molecules |
|
phospholipids
|
-compromises 75% of lipids
|
|
phospholipid bilayer
|
2 parallel layers of molecules
|
|
Describe the molecules in a phospholipid bilayer
|
2 parts
-polar parts(heads)are hydophilic and face on both surfaces a watery environment -non polar parts (tails) are hydrophobic and line up next to each other in the interior |
|
Glycolipids
|
sugar fat molecules
|
|
Glycolipids within the cell membrane
|
-compromises 5% of the lipids of the cell membrane
-carbohydrate groups form a polar head only on the side of the membrane facing the extracellular fluid |
|
cholesterol
|
stiff steroid ring inside of every cell wall
|
|
cholesterol within the cell membrane
|
-compromises 20% of cell membrane lipids
-interspersed among the other lipids in both layers -stiff steroid rings and hydrocarbon tail are nonpolar and hide in the middle of the cell membrane |
|
centrosome plays a role in
|
formation of cilia and flagella
|
|
2 types of membrane proteins
|
integral, and peripheal proteins
|
|
Describe peripheal proteins
|
attached to either inner or outer surface of cell membrane and are easily removed from it
|
|
Formation of channel
|
passageway to allow specific substances to pass through
|
|
transporter proteins
|
bind a specific substance, change their shape and move it across membrane
|
|
Receptor proteins
|
cellular recognition site bind to substance
|
|
Cell identity marker
|
allow cells to recognize other similar cells
|
|
linker
|
-anchor proteins in cell membrane or to other cells
-allow cell movement -cell shape and structure |
|
Act as enzyme
|
speed up reactions
|
|
Transmembrane proteins
|
protein extends completely across
|
|
What do glycoproteins do for the cell?
|
gives cell uniqueness, protects it from being digested creates a stickiness to hold it to other cells or so it can hold a fluid layer creating a slippery surface
|
|
Membranes are what type of structures?
|
fluid structures(oil layers)
- self sealing if punctured with a needle |
|
Membrane fluidity
|
a compromise of fluids --membrane molecules can rotate and move freely
-need to stay in one half of lipid bilayer -fluidity is reduced by presence of cholesterol |
|
Why does membranes need to stay in one half of the lipid bilayer?
|
Its difficult for hydrophilic parts to pass through hydrophobic core of bilipid layer.
|
|
Membrane Fluidity
Describe fluidity is reduced by presence of cholesterol |
increases stiffness of membrane it forms hydrogen bonds with neighboring phospholipid heads
|
|
Lipid bilayer
|
- permeable to nonpolar, uncharged molecules--oxygen, co2, steroids
- permeable to water which flows through gaps that form in hydrophobic core of membrane as phospholipids move about |
|
Transmembrane proteins act as specific channels.
|
small and medium polar and charged particles
|
|
Macromolecules unable to pass through the membrane.
|
vesicular transport
|
|
active transport
|
uses atp to drive substances against their concentration gradients. (walking up a hill)
|
|
passive transport
|
moves substances down their concentration gradient with only their kinetic energy. (jumping on a sled)
|
|
Vesicular transport
|
moves material across membranes in small vesicles either by exocytosis or endocytosis. (active)
|
|
Diffusion
|
random mixing of particles in a solution as a result of the particles kinetic energy
-more molecules move away from an area of high concentration to an area of low concentration -when the molecules are evenly distributed, equilibrium has been reached |
|
5 things about diffusion
|
-the greater the difference in concentration between the 2 sides of the membrane, the faster the rate of diffusion
-the higher the temp, the faster the rate of diffusion - the larger the size of the diffusing substance, the slower the rate of diffusion -an increase in surface area increases the rate of diffusion - increases diffusion distance, slows rate of diffusion |
|
Affects of tonicity on rbcs in lab
|
normally the osmotic pressure of the inside of the cell is equal to the fluid outside the cell
-cell volume remains constant (solution is isotonic |
|
Effects of fluids on rbcs in lab.
|
-water enters the cell faster than it leaves
-water enters and leaves the cell in equal amounts -water leaves the cell |
|
Isotonic solution
|
- water concentration the same inside and outside of cell results in no net movement of water across cell membrane
|
|
Hypotonic solution
|
higher concentration of water outside of cell results in hemolysis
|
|
Hypertonic solution
|
lower concentration of water outside of cell causes crenation
|
|
Diffusion through the lipid bilayer.
|
-important for absorption of nutrients--excretion of wastes
-nonpolar, hydrophobic molecules(oxygen, carbon dioxide, nitrogen, fatty acids, steroids, small alcohols, ammonia and fat-soluble vitamins a/e/d/k) |
|
Facilitated diffusion
|
-substance binds to specific transporter protein
-transporter protein conformational change moves substance across cell membrane |
|
Facilitated diffusion occurs down concentration gradient only
|
if no concentration difference exists, no net movement across membrane occurs
|
|
Rate of movement in facilitated diffusion depends upon
|
-steepness of concentration gradient
-number of transporter proteins(transport maximum) |
|
Osmosis
|
net movement of water through an area of high water concentration(low particle concentration) to an area of low water concentration.(high particle concentration)
|
|
When does osmosis occur?
|
only occurs if membrane is permeable to water but not to certain solutes
-diffusion through lipid bilayer -aquaporins (transmembrane proteins) that function as water channels |
|
Osmosis of water through a membrane
|
-pure water on the left side and a membrane impermeable to the solute found on the right side
-net movement of water is from left to right, until hydrostatic pressure (osmotic pressure) starts to push water back to the left |
|
Active transport
|
movement of polar or charged substances against their concentration gradient.
|
|
Active transport requires
|
energy
-energy from hydrolosis of atp (primary active transport) -energy stored in an ionic concentration gradient (secondary active transport) |
|
Active transport exhibits
|
transport maximums and saturations
|
|
lysosomes
|
Function -digest foreign substances
-autophangy(autophagosome forms) (recycles own organelles) -autolysis (lysosomal damage after death) |
|
Peroxisomes
|
function
-part of normal metabolic breakdown of amino acids and fatty acids -oxides toxic substances such as alcohol and formaldehyde -contains catalase which decomposes h2o2 |
|
Mitochondria
|
Function
-generation of ATP -powerhouse of cell |
|
Cytoskeleton
|
Functions
-cell support and shape -organization of chemical reactions -cell and organelle movement |
|
Cell organelles
|
-nonmembranous organelles lack membranes and are indirect contact with cytoplasm
- membranous organelles surrounded by one or two lipid bilayer membranes |
|
Primary and secondary active transport are
|
atp driven
|
|
Function of nucleus
|
46 human dna molecules or chromosomes
|
|
Ribosomes
|
the sites of protein synthesis
|
|
Golgi complex
|
processes and packages proteins produced by rough er
|
|
Vesicular transport of particles
|
endocytosis
exocytosis |
|
Endocytosis
|
bringing something into cell
-phagocytosis -pinocytosis -receptor mediated endocytosis=selective input |
|
Exocytosis
|
release something from cell
-vesicles form inside cell, fuse to cell membrane -release their contents(digestive enzymes, hormones, neurotransmitters or waste products) -replace cell membrane lost by endocytosis |
|
Phagocytosis
|
cell eating by macrophages and wbcs
-particle binds to receptor protein -whole bacteria or viruses are engulfed and later digested |
|
pinocytosis
|
cell drinking
-no receptor proteins |
|
Receptor-mediated endocytosis=selective input
|
mechanism by which hiv virus enters cells
|
|
Endoplasmic reticulum
|
network of membranes forming flattened sacs or tubles called cisterns
-half of membranous surfaces within cytoplasm |
|
Rough er
|
-continuous with nuclear envelope and covered with attached ribosomes
-synthesizes, processes and packages proteins for export -free ribosomes synthesize proteins for local use |
|
Smooth er
|
no attached ribosomes
-synthesizes phopholipids, steroids and fats -detoxifies harmful substances(alcohol) |
|
Gradients across the plasma membrane
substances move |
down their concentration gradient and towards the oppositely charged area
|
|
Gradients across the plasma membrane
membranes can maintain a difference in charged ions between |
inside and outside of membrane
|
|
Gradients across the plasma membrane
membrane can maintain difference in |
concentration of a substance inside versus outside of the membrane(concentration gradient)
|