AP Bio Unit 2

Eukaryotes

Organisms made up of one or more cells that have a nucleus and membrane-bound organelles, DNA in nucleus

Prokaryotes

Single celled organisms that do not contain nuclei and instead store DNA in the nucleoid. Also does not have membrane-bound organelles.

Plasma membrane

A selectively-permeable phospholipid bilayer forming the boundary of the cells. A "fluid mosaic" made of phospholipids, macromolecules, and proteins

Cell Wall

made up of carbs, surrounds the cells of plants and some other organisms

Cytoplasm

jellylike fluid inside the cell in which the organelles are suspended

Cytosol

Fluid portion of cytoplasm

Ribosomes

Site of protein synthesis, either found in the cytoplasm or on the rough ER. Not membrane bound, made of rRNA and proteins.

Rough ER

Network of membrane tubes studded with ribosomes; proteins are synthesized and packaged for possible export to the golgi.

Smooth ER

Network of membrane tubes; detoxifies cell, stores calcium ions, and is involved in lipid synthesis.

Golgi complex

Flattened membrane-bound sacs, receives and modifies proteins, preparing them for possible export out of the cell

Mitochondria

Double-membraned organelle, site of cellular respiration, or ATP energy production.

Lysosomes

Membraneous sac of hydrolytic enzymes used to digest macromolecules or break them down to reusable materials (monomers), acidic pH

Vacuoles

A membrane bound sac with a variety of uses; can store water/macromolecules, release waste, etc

Chloroplasts

Found in plant cells, a double membraned organelle that is the site of photosynthesis

Nuclear envelope

double membrane that surrounds the nucleus in the cell

Nuclear pores

Channels in the nuclear envelope that allow materials to pass in and out of the nucleus, connecting layers of the double membrane

Nucleoid

dense region of DNA in a prokaryotic cell

Nucleoli

Dense masses of RNA and protein that manufacture ribosomes, several of these are located in the nucleus.

Food vacuoles

fuses with lysosomes, uses enzymes to digest food

Contractile vacuoles

works to pump excess water out of a cell

Central vacuoles (plants)

formed by the merging of smaller vacuoles, play a major role in plant growth, store inorganic ions

Hydrolytic enzymes

found in lysosomes that speed up/aid in the breakdown of chemical bonds through hydrolysis

Cilia

Locomotor appendages that are short and numerous, can move fluid and receive signals

Flagella

Locomotor appendages that are long and whip-like, move like a fish tale, not many

Plasmodesmata

channels through plant cell walls that connect the cytoplasms of adjacent cells

Lumen

the space inside of an organelle, the space in the rough ER

Glycoproteins

have covalently bonded carbohydrate chains

Secretory proteins

destined for release from the cell

Peripheral proteins

loosely bound to the membrane surface or attached to an integral protein

Integral proteins

penetrate the lipid bilayer, usually spans the entire membrane

thylakoid

folded membrane compartments in stacks called grana, light dependent photosyntheisis reactions

stroma

fluid between inner chloroplast membrane and outer thylakoids, carbon fixation reactions

microvilli

projections that increase the cells surfact area

microtubules

hollow rod composed of tubulin proteins that makes up part of the cytoskeleton in all eukaryotic cells

cytoskeleton

network whos components are made of proteins that holds the cell together, helps to keep its shape, aids in movement

centrosome

region where the cells microtubules are initiated

chromatin

material consisting of DNA and proteins, visible as chromosomes in dividing cells

endoplasmic reticulum

network of membrane tubes in cytoplasm of eukaryotic cells

small cell size

easy to move materials in/out, smaller cell = more SA-V ratio

osmosis

diffusion specifically for water

isotonic

free water = solution, flacid

hypotonic

free water > solution, low concentration moves to high, turgid

hypertonic

free water < solution, high concentration moves to low, plasmolysis

fluid mosaic model

proteins bobbing in a fluid lipid bilayer of phospholipids, held together by hydrophobic interactions

aquaporins

channel proteins to help water get through plasma membrane

diffusion

movement of molecules from high to low concentration, small nonpolar molecules

concentration gradient

region along which the density of a substance increases/decreases

passive transport

moving down concentration gradient, doesnt require energy

osmosis

diffusion specifically for water, going from less concentrated solution to more for equilibrium

facilitated diffusion

high to low concentration with transport proteins, hydrophilic and charged ions

active transport

requires energy to move molecule up concentration gradient

membrane potential

voltage across a membrane

electrochemical gradient

chemical force (concentration gradient) and electrical force (effect of membrane potential on ions movement)

endocytosis

vesicle forms and transports macromolecules into cell (phagocytosis, pinocytosis, receptor mediated endocytosis)

exocytosis

vesicle transports macromolecules out of plasma membrane

cholesterol

steroid, randomly wedged between phospholipids, regulates bilayer fluidity

selectively permeable

small nonpolar can pass freely, hydrophilic/large polar cant pass freely

phagocytosis

cell takes in large particles

pinocytosis

cell takes in extracellular fluid containing dissolved substances

receptor mediated endocytosis

receptor proteins on the cell membrane are used to capture specific target molecules

tonicity

measure of the relative concentration of solute between two solutions

turgor pressure

cell wall expands and puts pressure on cell

water potential

measure of how likely water is to move from one location to another (solute and pressure potwntial)

solute potential

greater concentration of a solute, lower the water potential, inverse relationship, highest is zero

pressure potential

physical pressure increases water potential, direct relationship

compartmentalization

allows various metabolic processes and specific enzymatic reactions to occur simultaneously, increasing cell efficiency

endosymbiosis

one organism lives inside the other, internalization of prokaryotes by ancestral eukaryotes resulting in formation of mitochondria and chloroplast