Chap 3: Cells, Membranes, and Homeostasis

Of prokaryotic and eukaryotic cells, which have a nucleus, where is DNA located, which of the two have organelles?

prokaryotic —> no nucleus, eukaryotic = nucleus

prokaryotic —> DNA found in nucleoid, eukaryotic —> DNA found in nucleus

Prokaryotic —> no membrane-bound organelles, eukaryotic —> membrane-bound organelles

Phospholipids are amphipathic because they have both _____ heads and _____ tails

Hydrophilic polar heads, hydrophobic nonpolar tails

Lipid structures:

when in water, phospholipids spontaneously form a ____.

Polar heads and nonpolar tails associate with one another in a ____

liposome, bilayer

Lipid structure:

____ heads and ____ tails associate with one another in a bilayer

polar, nonpolar

basic lipid structures (3):

Micelle, bilayer, liposome

Membranes are a fluid _____

mosaic

- ____ and ____ are found in the membrane, forming a mosaic

- can move ____ within the membrane

- movement is affected by the nature of the _____ tails

lipids and proteins, laterally, phospholipid tails

Saturated vs unsaturated fatty acids:

______ interactions between the fatty acid tails help stabilize the membrane

van der waals

Saturated fatty acid chains lack double bonds, resulting in phospholipids with a _____ structure that favors tight packing

Unsaturated fatty acid chains have one or more double bonds that introduce ____ in the phospholipids, reducing the tightness of packing.

straight, kinks

Saturated fatty acid chains lack double bonds, resulting in phospholipids with a straight structure that favors ____.

Unsaturated fatty acid chains have one or more double bonds that introduce kinks in the phospholipids, reducing the ___-.

tight packing, tightness of packing

The amphipathic structure of cholesterol allows it to pack tightly with ___, limiting _____.

phospholipids, fluidity

Integral vs peripheral proteins

Integral proteins include transmembrane proteins that span the entire membrane

Peripheral proteins are temporarily associated with either the internal or external side of the membrane

What organelles are common to both eukaryotic and prokaryotic cells

Plasma membrane, cytoplasm, DNA, ribosomes

Nucleus:

contains ____

the ____ unit of the cell

____ membrane nuclear envelope

DNA, control, double

Mitochondria:

____ of cells

synthesizes ATP via _____

____ membrane organelle

contains its own _____ DNA

powerhouse, cellular respiration, double, circular

Golgi apparatus:

creates _____

modifies _____ and ____ by adding ______

also called?

vesicles

proteins, lipids, carbohydrates

sorting and packaging center

RER:

Has embedded _____ that synthesize ____ proteins (like insulin hormone) and ___ proteins.

ribosomes, secretory, membrane

SER:

Synthesizes ___ and ____

Can detoxify ____ and store ____.

lipids, steroids

drugs, calcium

Lysosome:

Digests unwanted cellular materials using ____ enzymes like:

Nucleases break ____ acids, ___, and ____.

Proteases break _____

Lipases break ___.

__ membrane-bound organelle

hydrolytic,

nucleic, DNA, RNA

proteins

lipids

single

Cell membrane:

The first ____ of the cell.

Limits ____ contents

maintains cellular _____.

structure bilayer phospholipids embedded with ____ and ____ proteins, ______, and _____ (found only in animal cells).

Is it membrane bound?

boundary, cellular, homeostasis, integral and peripheral, carbohydrates, cholesterol, not membrane bound

Ribosomes:

Function: ____ synthesis

Present free in the ____ and also embedded to ____.

is it membrane bound?

protein, cytoplasm, RER, not membrane bound

Chloroplast:

Function: Performs ____.

single or double membrane organelle?

contains its own ___ DNA.

photosynthesis, double, circular

photosynthesis uses ____, ___, and ___ as reactants to form products like ____ and ____.

CO2, water, sunlight, carbohydrates, oxygen

Cytoskeleton:

Function: ____ inside cells.

Helps ______ segregation.

Anchorage for _____ and _____ contraction.

movement, chromosome, organelles, muscular

Peroxisomes:

break down specific ___ molecules like fatty acids and synthesizes other organic molecules such as _____ and some type of phospholipids.

organic, cholesterol

Plant cell:

Cell wall is a rigid barrier composed of ?

polysaccharides

Plant cell:

Plasmodesmata connect _____ plant cells.

neighboring

Vacuoles (plant cell):

give plants structural rigidity by absorbing ____ and contributing to ___ pressure.

water, turgor

The _____ allows specific functions to take place within defined spaces of the cell using separatee cell structures.

endomembrane system

The endomembrane system:

______ and _____ are processes that occur when vesicles fuse with the cell membrane.

exocystosis and endocytosis

Exocytosis and endocytosis are processes that occur when ____ fuse with the ____.

vesicles, cell membrane

The ______ is a double membrane that surrounds the nucleus.

nuclear envelope

The nuclear envelope is a ______ membrane that surrounds the ___.

double, nucleus

RER produces ____, smooth RER produces ___.

proteins, lipids

The golgi apparatus modifies ____ and ____ produced in the ER.

Sorts proteins and lipids as they move to their ____.

Synthesizes the cell’s ____

proteins, lipids, final destination, carbohydrates

Lysosomes: specialized ____ derived from the golgi apparatus

degrade damaged or unneeded _____.

vesicles, macromolecules