Exam 2 - bio

chapters 4 & 5

cells

basic unit of life

tissues

interconnected cells with a common function

magnification

process of enlarging an object in appearance

resolution

ability to distinguish adjacent structures

Resolving power

Ability to see a clear distinct image

high resolution

more clarity and detail

compound light microscope

bend visible light to provide magnification

electron microscope

use beams of electrons to increase magnification and resolution

plasma membrane

separates the from the external environment

cytoplasm

gel liquid that fills cell, keeps organelles hydrated

DNA

genetic material found in cell

ribosomes

synthesize proteins

prokaryotes

lack membrane-enclosed internal compartments

prokaryotes cell wall contain

peptidoglycan

location of chromosomal DNA

nucleiod

prokaryotes are

smaller than eukaryotic cells

prokaryotes lack

modifications that aid in internal transport

phospholipid bilayer

plasma membrane

cytoplasm (eukaryotic)

region between the plasma membrane and the nuclear envelope, made of cytosol

nucleus

largest organelle, holds DNA

nuclear envelope

double membrane that separates DNA from cytoplasm

nuclear pores

regulate the flow of molecules in and out of the nucleus

Nuclear pores connect

Nucleoplasm and cytoplasm

nucleolus

region where rRNA is synthesized and ribosomes are assembled, materials needed for protein synthesis

where chromosomal DNA is localized in prokaryotes

nucleoid

ribosomes

synthesize proteins

mitochondria

site for conversion of stored energy, convert glucose into CO2 and ATP

found in animal cells only

centrosome and lysosome

cristae

inner membrane folds of the mitochondria

animal cells lack

cell wall, chloroplasts, central vacuole

centrosome

involved in cell division

cell wall

protective structure external to the plasma membrane

plant cell wall is made up of

cellulose

chloroplast

contains chlorophyll and thylakoids

chloroplasts contain

their own ribosomes and DNA

central vacuole

helps regulate water concentration

endosymbiosis

the mitochondria and chloroplasts originated independently as prokaryotes

lysosomes

breakdown large biomolecules and worn out organelles

Endoplasmic Reticulum

interconnected membranous sacs and tubules that modifies proteins

Rough Endoplasmic Reticulum

ribosomes attached to the surface, modifies new proteins to incorporate or secrete from cell and makes phospholipids

smooth endoplasmic reticulum

has no ribosomes attach to the cytoplasmic surface, synthesis of carbohydrates, lipids, steroid hormones, detoxification of medicine and poisons and storage of Ca+2

smooth endoplasmic reticulum in muscle cells stores Ca+2

muscle contraction

Golgi apparatus

Sorts, packages and tags the lipids and proteins within transport vesicles

receiving side of the Golgi

cis face

exporting side of the Golgi

trans face

transport vesicles for the ER fuse with the ___ of the Golgi body

cis face

cytoskeleton

network of protein fibers that help maintain the shape of the cell, hold organelles place, allow movement of cytoplasm and cells as a whole

components of the cytoskeleton

microfilaments, intermediate filaments, microtubules

microfilaments

involved in movement, determine and stabilize shape

microfilaments are made of

actin monomers

microtubules

form rigid internal skeleton and framework for motor proteins,

microtubules are made of

tubulin dimers

cilia & flagella

allow for cellular movement

plant cell wall

provide support and act as a barrier to infection

extracellular matrix is made of

colognes, glycoproteins and linking proteins

intercellular junctions

provide direct channels of communication between cells

plasmodesmata

channels between cell walls that allow for the movement of materials between plant cells

tight junctions

watertight seals between animal cells that prevent materials from leaking

tight junctions are found in

epithelial cells

desmosomes

short proteins in the plasma membrane that act a spot welds by joining adjacent tissues

desmosomes are only present in

animal cells

gap junctions

protein lined channels between animal cells that allow ions and other materials to move between cells

connexon

elongated donate that form gap junctions

fluid mosaic model

mosaic of components that give the cell membrane a fluid character

polar head of phospholipids face

outward

the polar head of a phospholipid is

hydrophilic

the non polar tail of the phospholipid face

inward

the non polar tail of a phospholipid is

hydrophobic

in the cell membrane proteins function as

transporters, receptors, enzymes and binding and adhesion factors

integral proteins

with a hydrophobic and hydrophilic region that passes through the membrane

oligosaccharide carbohydrates are located

on the exterior surface of the plasma membrane and are bound to lipids or protein

oligosaccharide carbohydrates

function in cell to cell recognition and attachment

membrane fluidity is affected by

phospholipid type, temperature and cholesterol

cold temperatures

compress molecules and make the plasma membrane more rigid

cholesterol

acts as a fluidity buffer and keeps membranes fluid when in cold temperatures and more rigid when in higher temperatures

phospholipids with saturated fatty acids

pack together more closely making the membrane more rigid

plasma membrane are

asymmetric

receptor proteins

glycoproteins on the cell membrane that are responsible for cell to cell recognition and controlling what enters the cell

the plasma membrane is

selectively permeable

selectively permeable

only allowing some molecules to pass

can pass through the membrane

gases, non polar molecules, small polar molecules

cannot pass through the membrane

large polar molecules, ions

passive transport

requires no energy

active transport

requires energy

passive transport occurs when

a substance moves from a high concentration to a low concentration

concentration gradients

difference in concentration of solutions

small molecules

diffuse more quickly

at high temperature

molecules move faster

dehydration causes

solvent density to increase and diffusion rates to decrease

the more non polar materials

diffuse faster

increased surface area

faster diffusion

the greater the distance travelled

slower rate of diffusion

high pressure

faster diffusion

facilitated transport

moves substances from high to low concentration rations through integral proteins

facilitated transport diffuse

ions and polar molecules

two types of facilitated transport proteins

channel and carrier proteins

channel proteins can be

open or gated

gated channel proteins

require a signal

all carrier proteins are

specific to a single substance