AP Bio unit 2

Cytoplasm

A jellylike fluid inside the cell in which the organelles are suspended

Endoplasmic Reticulum

A cell structure that forms a maze of passageways in which proteins and other materials are carried from one part of the cell to another.

Ribosome

Makes proteins

Lysosome

An organelle containing digestive enzymes

Vacuoles

Cell organelle that stores materials such as water, salts, proteins, and carbohydrates

Cell wall

A rigid layer of nonliving material that surrounds the cells of plants and some other organisms.

Eukaryote

A cell that contains a nucleus and membrane bound organelles

Prokaryotic Cells

do not have a nucleus or other membrane-bound organelles

Smooth ER

a membrane-bound cell organelle that builds fats, makes steroid hormones, and cleans up toxins

Golgi apparatus

A system of membranes that modifies and packages proteins for export by the cell

Mitochondria

Powerhouse of the cell, organelle that is the site of ATP (energy) production

Surface area to volume in cells

the surface area to the volume ratio gets smaller as the cell gets larger

nucleolous function

produces RNA and ribosomes

endomembrane system

makes, processes, and transports materials using structures such as the ER, Golgi apparatus, and vesicles.

Cristae

Infoldings of the inner membrane of a mitochondrion that houses the electon transport chain and the enzyme catalyzing the synthesis of ATP.

matrix of mitochondria

Chloroplasts

Capture energy from sunlight and use it to produce food for the cell

Thylakoids

A flattened membrane sac inside the chloroplast, used to convert light energy to chemical energy.

stroma of the chloroplast

Where chloroplast DNA is

Cytoskeleton

A network of fibers that holds the cell together, helps the cell to keep its shape, and aids in movement

Microtubules

Spiral strands of protein molecules that form a tubelike structure

Helps in cell division

cillia

flagella

Prokaryotic Cell wall

peptidoglycan

Microfilaments

Long, thin fibers that function in the movement and support of the cell

• used in muscle contraction

Intermediate filaments

Threadlike proteins in the cell's cytoskeleton that are roughly twice as thick as microfilaments

. Intermediate filaments provide strength and stability to cells. They are part of the cytoskeleton and help:

• Maintain cell shape.

• Anchor the nucleus and other organelles.

• Resist stretching and mechanical stress.

• Support the nuclear envelope.

extracellular matrix

The extracellular matrix (ECM) is a network of proteins and carbohydrates outside animal cells that supports and connects them.

endosymbiotic theory

theory that eukaryotic cells formed from a symbiosis among several different prokaryotic organisms

Integral Membrane proteins

proteins that are at least partially embedded in the plasma membrane

Peripheral membrane proteins

proteins associated with but not embedded within the plasma membrane

Roles of membrane proteins

transport, enzymatic activities, signal transduction, cell-cell recognition, intercellular joining, attachment to the cytoskeleton, attachment to the extracellular matrix

Glycocalyx

layer of sugar groups outside the cells

• glycoproteins + glycolipids

• for cell to cell recognition

Cholesterol cell membrane

helps stabilize the membrane fluidity

• low temps --> more cholesterol

Selective permeability

A property of a plasma membrane that allows some substances to cross more easily than others.

What can not cross the membrane easily

• polar molecules

• large molecules

• hydrophilic molecules

What can cross the membrane easily

• small hydrophobic molecules

Passive transport

the movement of substances across a cell membrane without the use of energy by the cell

aquaporins

water channel proteins

Water potential

The physical property predicting the direction in which water will flow, governed by solute concentration and applied pressure.

Solute potential

increasing amount of solute --> decreasing water potential

Hypertonic

when comparing two solutions, the solution with the greater concentration of solutes

Hypotonic

Having a lower concentration of solute than another solution

Facilitated Diffusion

Movement of specific molecules across cell membranes through protein channels

Bulk transport

The process by which large particles and macromolecules are transported through plasma membranes. Inc. exocytosis and endocytosis

Exocytosis

Process by which a cell releases large amounts of material

Endocystosis

the process during which a cell takes in a substance by surrounding it with the cell membrane

Which of the following is a major cause of the size limits for certain types of cells?

• a. limitation on the strength and integrity of the plasma membrane as cell size increases

• b. the difference in plasma membranes between prokaryotes and eukaryotes

• c. evolutionary progression in cell size; more primitive cells have smaller sizes

• d. the need for a surface area of sufficient area to support the cell's metabolic needs

• e. rigid cell walls that limit cell size expansion

• d. the need for a surface area of sufficient area to support the cell's metabolic needs

A cell has the following molecules and structures: enzymes, DNA, ribosomes, plasma membrane, and mitochondria. It could be a cell from

• a. a bacterium

• b. an animal, but not a plant

• c. nearly any eukaryotic organism

• d. any multicellular organism, like a plant or an animal

• e. any kind of organism

• c. nearly any eukaryotic organism

Movement of vesicles within the cell depends on what cellular structures? 

• a. microtubules and motor proteins

• b. actin filaments and microtubules

• c. actin filaments and ribosomes

• d. centrioles and motor proteins

• e. actin filaments and motor proteins

• a. microtubules and motor protein