PPt.13: Cell Structure & Function Unit 2 Flashcards
All living things are composed of cells
Cell theory
Most of cells metabolic activity occurs here
Cytoplasm
Integral membrane proteins are suspended individually in the fluid phospholipid bilayer
Fluid mosaic model
Attached to integral proteins or membrane lipids on cytoplasmic side of membrane
Peripheral Proteins
Used to distinguish your own cells from those of disease-causing microbes
Recognition Proteins
Deliver chemical messages that act like switches to turn certain cell functions on or off when certain substances bind to them
Receptor Proteins
Involves the movement of substances from an area of higher concentration to lower concentration
- passive process
- oxygen diffuses into red blood cells while CO2 diffuses out
Simple diffusion
A special case of diffusion involving the movement of water across a selectively permeable membrane in response to differences in solute concentrations on either side of the membrane
-Low solute concentration to high
Osmosis
Relative concentration of solutes on either side of cell membrane
Tonicity
One in which the concentration of solutes is the same on inside and outside of cell
Isotonic solution
(fresh water) the concentration of solutes is lower than that of the inside of the cell
Hypotonic solution
(salt water) the concentration of solutes is higher than that of the inside of the cell
Hypertonic solution
Channel proteins in cell membranes that allow water to pass through the membrane
Aquaporins
Although gases pass easily through cell membranes by simple diffusion, most water-soluble molecules cannot cross the lipid bilayer
Facilitated diffusion
Form pores in the bilipid layer through which certain ions can pass
Channel proteins
Stable membrane
Resting potential
Grab onto a specific kind of molecule on one side of the membrane and carry to other side
-must bind to solute
Carrier proteins
Insulin-regulated glucose transporter
Glut4
Although passive transport is efficient and requires no energy, sometimes it is necessary to move ions or molecules against a concentration gradient
Active Transport
The sum of the concentrations of the various ions, proteins and other organic compounds inside the cell
Osmolarity
Sometimes cells must take in particles or droplets of fluid that are too large to move across a cell membrane by either passive or active transport
Endocytosis
Membraneous sac
Vesicle
Engulfing particular material
Phagocytosis
Engulfing liquid material
Pinocytosis
Process highly specific and fast
Receptor mediated
Cells create wastes or synthesized compounds to the outside
Exocytosis
In eukaryotic cells, controls and regulates most cellular activity
Nucleus
Composed of DNA and proteins which contain genes that control activities of cells
Chromosomes
Ribosomes are manufactured here
Nucleoli
Composed of RNA and proteins, “work bench”
Ribosomes
Series of interconnected, membrane-bound channels that pass from nuclear membrane through the cytoplasm
Endoplasmic Reticulum ER
Coated with ribosomes which make proteins
Rough ER
Phospholipids and cholesterol form membranes and are found here
Smooth ER
Packages proteins inside the cell before they are sent to their destination
Golgi apparatus
Membrane-bound packages
Vesicle
Stacks of membrane-bound structures’ secretory pathway
Cisternae
Digestive enzymes that can break down complex biological molecules into component subunits
Lysosomes
Fluid-filled spaces found in plants and animals
Vacuoles
In plants, occupies most of the space in mature cell and stores waste products
Central Vacuole
Excretes excess water, enters by osmosis
Contractile vacuole
Powerhouses, energy is extracted from food molecules and stored in high-energy bonds of ATP, Double membrane and inner membrane
Mitochondria
Deep folds on inner layer
Cristae
Organelles found in plants cells that contain pigments and enzymes necessary for converting sunlight energy into chemical bond energy during photosynthesis
Chloroplasts
Green, light-absorbing pigment
Chlorophyll
Stacks of structures in third membrane
Thylakoid
Fluid around thylakoid stacks
Stroma
Network of fibers and microtubules composed of proteins contained within cell’s cytoplasm, provides shape and support for cell, anchors organelles, used in vesicle transport
Cytoskeleton
Thin moveable extensions of the plasma membrane made of microtubules that allow some cells to move through liquid medium
Cilia and Flagella
Outside of the plasma membrane in bacteria, fungi and plants is a rigid, non-living structure that provides support and protection for cells
Cell Wall
Small holes that allow transport and communication
Plasmodesmata
Polymer in bacteria cells only consisting of sugar and amino acids
Peptidoglycan
Eukaryotes arose by a fusion of several small, specialized prokaryotes into a larger, unspecialized one that benefited from the union
Endosymbiont Theory
Why don’t Na+ ions cross plasma membrane all the time?
They can’t get through semi-permeable plasma membrane
What would make Na+ ions want to go into the cell?
Na+ ion concentrations are higher outside a cell than inside a cell (concentration gradient)
Travel from one neuron and bind to the plasma membrane of the next
Neurotransmitters
Released at neuromuscular junctions
Acetylcholine
Released from neurons
Norepinephrine
Contains rough ER and Golgi
Nerve cell body
Conduct nerve impulses toward nerve cell body
Dendrites
Conducts electrical impulses away from nerve cell body clostridium botulinum block release of acetylcholine from neurons inhibiting exocytosis of transport vesicles containing acetylcholine
Axon
