Biology 1406 Exam 2

Why is it more beneficial for cells to be smaller rather than larger ?

able to diffuse through materials easily, easier to replicate and replace when damaged.

Organelles

enclosed structures in Eukaryotic cells.

Prokayotic Cells

DNA is not enclosed ; inside Nucleoid

Bacteria and Archaea.

Prokaryotic Cells

Protists, fungi animals and plants.

Eukaryotic Cells.

Eukaryotic Cells

DNA is in organelle called the Nucleus.

Nucleoid

Area inside prokayotic cells that houses DNA.

What are the characteristics of a Prokayotic Cell ?

Fimbriae, Nucleoid, Ribsosomes,Plasma Membrane, Cell Wall, Capsule, Flagella.

Fimbriae

attachment structures on the surface of some prokaryotes.

Ribosome

complexes that synthesis proteins; uses information from DNA to make proteins

Plasma membrane

encloses the cytoplasm

Cell Wall

rigid structure outside the plasma membrane;maintains cell's shape; made of cellulose, polysaccharides, and protein.

Capsule

Jellylike outer coating of many prokaryotes

Flagella

locomotion organelles of some bacteria

Cytoplasm

the interior of either type of cell.

Which of the two cell types are larger in size ?

Eukaryotic Cells

The smallest cells known are a bacteria called ?

mycoplasmas

function of the plasma membrane

a selective barrier that allows passage of enough oxygen, nutrients and wastes to service the entire cell.

as a cell increases in size..

its surface area grows less than its volume.

Microvilli

projections that increase the cell's surface area and not volume.

Enzymes

embedded in mitochondria; function in cellular respiration

organelles of an animal cell.

Endoplasmic Reticulum, Nucleus, Plasma membrane, Ribosomes, Golgi apparatus, Lysosome, Mitochondrion, Peroxisome, Cytoskeleton, Centrosome, & Flagellum.

Flagellum

motility structure present in some animal cells.

Centrosome

contains a pair of centrioles

Cytoskelton

includes (mircofilaments, intermediate filaments, mircotubles) reienforces cell's shape; functions in cell movement.

Mitochondrion

where ATP cellular respiration occurs and most ATP is generated; contains some DNA

Lysosome

digestive organelle where macro-molecules are hydolyzed

Hydrolyze

break down of a chemical reaction with water.

Golgi apparatus

acts in synthesis modification,sorting, and secretion of cell products.

Peroxisome

specializes in metabolic functions; produces hydrogen peroxide as a by-product then converts it to water.

What organelles are in plant cells that are not included in animal cells ?

Cell Wall, Vacuole, Chloroplast, & Plasmodesmata.

Plasmodesmata

channels thorough cell walls that connect the cytoplasm of adjacent cells.

Chloroplast

aides photosynthesis; converts energy of sunlight to chemical energy stored in sugar molecules.

Vacuole

responsible for storage; breakdown of waste products and hydrolysis of macromolecules

Nucleus

houses most the cells DNA; directs protein synthesis by synthesizing messenger RNA

Nuclear Envelope

double membrane; encloses the nucleus , separating its contents from the cytoplasm.

pore complex

regulates the entry and exit of proteins and RNA's

Lamina

protein filaments that maintains the shape of the nucleus.

nuclear matrix

framework of protein fibers extending throughout the nuclear interior

Chromatin

the complex of DNA and proteins making up chromosomes

The typical human has how many chromosomes in it's nucleus ?

46

RNA( Ribosomal RNA)

synthesized from instructions in the DNA

Cells that have high rates of proteins synthesis have...

particularly large numbers of ribosomes.

free ribosomes

suspended in the cytosol

bound ribosomes

attached to the outside of the endoplasmic reticiculum or nuclear envelope.

Ribosomes can alternate between two roles

True

what are the organelles of the endomembrane system?

nuclear envelope, endoplasmic reticulum, golgi apparatus,lysosomes,vesicles, vacuoles,and plasma membrane

Cisternae

sacs

Smooth ER

outer surface lacks ribosomes; synthesis of lipids,metabolism of carbohydrates, detoxification of drugs and poisons and storage of calcium ions.

Rough ER

studded with ribosomes; makes membrane phospholipids; assemble phospolipids from precursors in the cytosol.

Detoxfication

adding hydroxyl groups to drug molecules making them more soluble and easier to flush from the body.

Cisternal maturation

golgi cisternae themselves mature; moving from cis to trans while carrying some proteins

Phagocytosis

lysosome digesting food

Autophagy

lysosome braking down damaged organelles

Extracellular Matrix (ECM)

regulates a cells behavior through communication through integrins; glycoproteins & carboyhydrate molecules

Integrins

transmits signals between the ECM and cytoskeleton; to integrate changes inside and outside the cell.

What proteins interact with the ECM ?

integrins and fibronectin

tight junctions

the plasma membranes of cells, very tightly pressed against each other ; prevents leakage of extracellular fluid across a layer of epithelial cells

demosomes

fastening cells together into strong sheets; attach muscle cells to each other in muscle

Gap junctions

provides cytoplasmic channels from on cell to an adjacent cell

amphipathic

hydrophillic and hydrophobic region

what molecules can move through the selective permeability of the membrane ?

Non polar; hydrophillic molecules; with no charge.

cholesterol

reduces membrane fluidity at moderate temperatures, by reducing phosoholipids movement

integral proteins

penetrate the hydrophobic interior of the lipid bilayer

peripheral proteins

loosely bound to the surface of the membrane

what are the six functions of proteins ?

Transport, Enzymatic Activity, Signal transduction, cell-cell recognition, intercellular joining, attachment to cytoskelton and extracellular matrix

how does polar molecules cross the membrane ?

transport proteins

diffusion

the movement of particles of any substance so they spread out into available space.

osmosis

water molecules moves from an area of higher to lower free water concentration

passive transport

substances diffuse down their concentration gradients

active transport

substances move across membrane against their concentration