AP BIO UNIT 2 TEST

Cellular metabolism depends on

cell size

What happens when a cell gets too large?

it begins to be difficult to regulate what comes in and out of the cell

The size of the cell will determine

it's function

Cells need ___________ to optimize the exchange of material through the plasma membrane

a high surface area to volume ratio

Separates internal cell environment from external cell environment

plasma membrane

What is the plasma membrane made up of?

phospholipids

What are phospholipids in regards to charge?

amphipathic

How does the cell membrane create a bilayer?

the hydrophilic heads facing towards the environment and the nonpolar tails facing inward

A model to describe the structure of cell membranes

fluid mosaic model

Why do they call it a fluid mosaic model

cell membrane is held together by weak, hydrophobic interactions that can make it move and shift and is comprised of many macro molecules

How does cholesterol help maintain fluidity?

reduces movement in high temperatures and reduces tight packing in low temperatures

What are the two major categories of proteins in the membrane?

integral proteins and peripheral protein proteins

Proteins that are embedded into the lipid by layer in our determined by R groups

integral proteins

What makes up an integral protein?

interior is hydrophilic and exposed to the side of salt and the channel is hydrophobic

Proteins that are not embedded into the lipid bilayer and are bonded loosely to the surface

peripheral protein proteins

Purpose of membrane carbohydrates

cell to cell recognition

What are the two types of membrane carbohydrates?

glycolipids and glycoproteins

The ability of membranes to regulate the substances that enter and exit the cell

selective permeability

How can selective permeability occur?

non-polar hydrophobic tails of phospholipids

What substances can easily pass across the membrane?

small, nonpolar, hydrophobic molecules

What molecules is it hard to pass through the cell membrane or need protein assistance?

hydrophilic, polar molecules, large molecules, and ions

What are the function of cell walls?

provide structural boundary permeability barrier for some substances protection from osmatic lysis

What does a cell wall contain?

plasmaodesmata

What are the two types of transport across a membrane?

passive and active

Transport of a molecule that does not require energy from the cell because it is a solute moving within its electrochemical gradient

passive transport

Three types of passive transport

diffusion, osmosis, and facilitated diffusion

Spontaneous process, resulting from the constant motion of molecules

diffusion

What happens in diffusion?

substances move from high to low concentration down the concentration gradient to achieve dynamic equilibrium

The diffusion of water down its concentration gradient across a selectively permeable membrane

osmosis

Diffusion of molecules through the membrane via channel or carrier proteins; does not require energy

Facilitated diffusion

Form a pore/channel in the membrane and have gates that can open in response to stimuli

channel proteins

Specialized channel proteins for water water

aquaphorins

Alternate between two confirmations and help move large polar molecules (glucose, amino acids, and nucleosides)

carrier proteins

Transport of a molecule that requires energy because it is moving against its concentration ingredient

active transport

What does active transport require?

ATP

What are the types of active transport?

pumps, transport, exocytosis endocytosis

How does ATP transport its energy?

transfers, terminal phosphate group to transport protein to help move the substance

Maintain membrane potential

pumps

Unequal concentrations of ions across the membrane and results to electrical charge

membrane potential

Proteins that generate voltage across membranes, which can be used as an energy source for cellular processes

electrogenic pump

How animal cells will regulate their relative concentrations of NA and K

sodium potassium pump

How does the sodium potassium pump work?

three NA pumped out of the cell and two K pumped into the cell

Integral membrane protein that builds up a proton gradient against the membrane by pumping hydrogen out of the cell

proton pump

Coupling of favorable movement of one substance with an unfavorable movement of another substance

transport

Example of co-transport

sucrose can only travel against its concentration ingredient if hydrogen is diffusing down the gradient

Two ways large substances are moved in and out of the cell

endocytosis and exocytosis

The secretion of molecules via vesicles that fuse to the plasma membrane by forming a bilayer

exocytosis

The uptake of molecules from vesicles fused to the plasma membrane

endocytosis

Type types of endocytosis

phagocytosis, pinocytosis and receptor-mediated

When a cell engulf particles to later be digested by lysosomes

phagocytosis

How does phagocytosis take place?

cell surrounds particle with pseudopodia and packages particles into a food vacuole to be used with a lysosome

Nonspecific uptake of extracellular fluid containing dissolved material materials

pinocytosis

Specific uptake of molecules via solute binding to receptors on the plasma membrane

receptor mediated endocytosis

the basic structural and functional units of every organism

cell

what do all cells have

plasma membrane, cytosol, chromosomes, ribosomes

what are the 2 types of cells

prokaryotic and eukaryotic

what do prokaryotic cells have

bacteria, domains, archea

DNA in nucleoid

small in size compared to eukaryotes

lack membrane bound organelles

unicellular

what do eukaryotes have

protists, fungi, plants, animals

DNA in nucleus

contain membrane bound organelles

compartmentalize cellular functions

membrane bound structures in eukaryotes

organelles

organelles and subcellular components that interact to modify, packagem and transport polysaccharides, lipids, and proteins

endomembrane system

organelles in endomembrane system

nuclear envelope, ER, golgi, lysosomes, vacuoles, vesticles, plasma membrane

convert energy to forms that the cell can use for work

energy organelles

organelles that are energy organelles

mitochondira, and chloroplasts

different metabolic processes happening in different locations; increase surface area and prevent interfering reactions from occuring in the same location

compartmentalization

can prokaryotes have compartmentalization

yes

what does plant cells have that are unique to the cell

cell wall, chlorplasts, plasmodesmata, central vacuole

what do animal cells have that are unique to the cell

lysosomes, centrosomes, flagella

surrounds the nucleus and all of its components

nuclear envelope

surrounded by nuclear envelope, double membrane, has pores that regulate entry and exit

nucleus

dense region where ribosomal RNA (rRNA) is synthesized

nucleolus

_____ is combined with _____ to form large and small subunits of ribosomes

rRNA; proteins

ribosomes translate messages found on mRNA into the

primary structure of poly peptides

comprised of RNA and protein

ribosomes

function of ribosomes

synthesize proteins

where can ribosomes be found

cytosol and ER

network of membranous sacs and tubules

ER

functions of ER

mechanical support by maintaining cell shape and transport within the cell

2 types of ER

rough and smooth

function of rough ER

contains ribosomes bound to ER membrane

compartmentalizes protein synthesis

function of smooth ER

synthesis of lipids and detoxification of the cell

membranous sacs in ER and golgi

cisternae

function of golgi

recieves transport vesticles from Er, modifies/sorts materials, adds molecular tags, packages new materials

2 faces of golgi

cis face and trans face

recieves vesticles from ER

cis face

sends vesticles back out of golgi into the cytosol to other locations or to the plasma membrane

trans face

membranous sac with hydrolytic enzymes in animal cells

lysosomes

function of lysosmes

digests/eats macromolecules, autophage, plays a role in apoptosis

lysosomes can recycle their own cells orginal matrix and organelles that are not functioning properly

autophagy

steps of autophagy

membrane formed around bad organelle —> fuses with lysosome —> enzymes break down the organelle and components are recycled

membrane bound metabolic compartments that detoxifies the cell

peroxisomes

how do peroxisomes detoxify the cell

produce H2o2 to detoxify and then enzyme breaks it down to water and oxygen

stem from ER to golgi and involved transport

The transport vesicles

aminal cell vacuoles

small in size, store materials, assist in endocytosis and exocytosis

plant cell vacuoles

one large central vacuole, stores nutrients and water for turgor pressure, function like lysosomes

site of cellular respiration and has a double membrane; location for krebs cycle

mitochondria

describe membranes of mitochondria

outer membrane is smooth and inner membrane has folds called cristae, which increase surface area for ATP production.

space between inner and outer membrane in mitochondria

intermembrane

enclosed by inner membrane

mitochondrian matrix

number of mitochondria correlates with

metabolic activity

specialized organleed for plants and algae that is the site of photosynthesis; contains chrolophyll

chloroplast