Chapter 3: Cell Structure and Function Flashcards
Cell membrane
Lipid bilayers
Provides isolation, protection, sensitivity and support; controls ent/exit or materials
Cytosol
Fluid component of cytoplasm;distributes by diffusion
Cytoskeleton
Made up of microfilaments, intermediate filaments and microtubules
Provides stregnth and support; enables movement of cell structures and materials
Microvilli
Memebrane ext that contain microfilaments
Increase surface area to facilitate absorption of extracellular materials
Cilia
Membrane extensions that contain microtubules
Move materials over surface of cell
Flagella
Long, whip-like filament that moves cell through fluid
In humans only,found in sperm cells
Centrioles
Composed of microtubules; cylindrical structure
Essential for movement of chromosomes during cell division
Ribosomes
RNA+proteins
fixed ribosomes bound to ER
Free ribosomes scattered in cytoplasm
Synthesize proteins
Proteasomes
Cylindrical structures that contain proteases (protein-breaking enzymes)
Break down and recycle damaged or abnormal intracellular proteins
ER
Network of membranous channels that extend throughout the cytoplasm; may be smooth or rough
Synthesizes secretory products; provide (IC) storage and transport
Smooth (ER)
Lacks attached ribsomes
Synthesize lipids and carbs
Rough (ER)
Has ribosomes attached to membrane
Packages newly synthesized proteins
Golgi apparatus
Stacks of flattened memebranes that contain chambers
Stores, alters, packages secretory products
form lysosomes
Lysosomes
Vesicles that contain powerful digestive enzymes
remove damaged organelles or pathogens within cells
Peroxisomes
Contain degradative enzymes
Catabolize fats and other organic compounds; neutralize toxic compounds (hydrogen peroxide) generated in the process
Mitochondria
Double memebrane with inner folds
95% of ATP produced
Nucleus
Contains DNA, nucleotids, enzymes and proteins
Control metabolism; stores and processes genetic information; controls protein synthesis
Nucleolus
Contains DNA and RNA
Synthesizes RNA and assembles ribosomal subunits
Receptor proteins
Sensitive to specific extracellular materials that bind to them and trigger a change in a cell’s activity
Channel Proteins
Central pore/channel permits water, ions, and other solutes to bypass lipid portion of the cell membrane
Carrier proteins
Bind and transport solutes across cell membrane
Anchoring proteins
Attach cell membrane to other structures and stabilize its position
Recognition (identifier) proteins
Identify a cell as self or non self, normal or abnormal, to the immune system
Diffusion
Movement of molecules from high to low cocentration of solutes
Osmosis
Diffusion of water from low to high solute concentration
Filtration
Movement of material through a membrane as a result of hydrostatic pressure
Facilitated diffusion
Carrier proteins passively transport solutes down a concentration gradient
Active transport
Carrier proteins actively transport solutes regardless of any concentration gradient (uses ATP)
Endocytosis
Importing into cell; may be receptor mediated, pino or phagocytosis
Receptor mediated endocytosis
Movement of specific molecules inward by vesicles containing protein receptor sites; cell acquires bulk quantities
Osmotic pressure
Force of water movement into a given solution as a result of solute concentration “pull” force
Hydostatic pressure
Pushing against a fluid; opposes osmotic pressure
Histones
Protein molecules around which DNA is tightly coiled
Chromatin
Tangle of the fine DNA filaments
Protein synthesis
Assembly of protein ribosomes; 2 steps; transcription and translation
Transcription
RNA polymerase (COPIES DNA sequence and makes it RNA requence) binds to a gene and promotes synthesis of an mRNA strand; creates sequence complementary to DNA
Translation
Synthesis of new proteins using mRNA information; tRNA delivers amino acids
Mitosis
Ordinary cell division
Meiosis
Sexual cell division
Interphase
Time between cell divisions
G1 Phase
Interphase where cell grows and performs its normal functions; organelles are duplicated (8+hours)
S phase
DNA is replicated in the nucleus (6-8hrs), synthesis of histones
G2 phase
rapid cell growth; protein synthesis, (2-5 hrs)
M phase
mitosis; formation of 2 identical nuclei (1-3 hrs)
Cytokinesis
Division of the cytoplasm into 2 distinct cells; begins in late anaphase
4 stages of mitosis
prophase, metaphase, anaphase, telophase
Prophase
Chromosomes become visible, nuclear envelope dissolves, spindle forms/attaches to chromatids, pairs of centrioles go to poles
Metaphase
Chromosomes line up in the middle of the cell along metaphase plate
Anaphase
Centromere splits, chromatids seperate, daughter chromosomes go to opposite cells
Telophase
Nuclear membranes start to form, chromosomes begin to uncoil, spindle fibers fall apart
Centromere
Region of a chromosome where two sister chromatids attach
Chromatid
One half of a duplicated chromosome
Hemolysis
Rupture of red blood cells
Crenation
Shinking of RBCs
Isotonic
Concentration of 2 solutions is the same
Hypotonic
Solution with lower solute concentration
Hypertonic
Solution with high solute concentration
Malaria
Most infectious disease; cauzed by protozoa
Phospholipid membrane
Allows lipid soluble molecules to cross (O2 and CO2) but not ions and water soluble compounds
Concentration gradient
Difference in concentration from one another
Intracelluar cation
Potassium (K+)
Extracellular cation
Sodium (Na+)
Apoptosis
Programmed cell death
Crystalloids vs colloids
Both volume expanders
Crystalloids- aqueous solutions of mineral salts or other water soluble molecules
Colloids- Larger insoluble molecules such as gelatin; blood