AP Biology Chapter 4 - Tour of The Cell

cytosol

semi fluid, jellylike substance in the cell

cytoplasm

all organelles + cytosol of the cell, between the cell membrane and the nucleus

cell membrane

bilayer of phospholipids that surrounds the cell and functions to regulate what enters and exits the cell

nucleus

control center of the cell containing DNA and MRNA

nuclear envelope

surrounded by double membrane, continuous with rough endoplasmic reticulum

nuclear pores

control what enters + leaves the nucleus

chromatin

complex of DNA and proteins; makes up chromosomes

nucleolus

region where ribosomal subunits (rRNa + proteins) are formed

ribosomes

makes polypeptide chains through protein synthesis

structure of ribosomes

composed of rRNA and protein, can be large or small subunits

free ribosomes

floats in the cytosol, produces proteins used within a cell

bound ribosomes

attached to the endoplasmic reticulum makes proteins for export from cell

endomembrane system

regulated protein traffic, performs metabolic functions

endoplasmic reticulum

rough ER

cisternae

network of tubules and sacs- separated endoplasmic reticulum lumen from the cytosol

lumen

cavity in the endoplasmic reticulum

rough endoplasmic reticulum

ribosomes bound on surface

• packaged proteins for secretion, send transport vesticles to golgi, make replacement membrane

transport vesticles

small membrane bound sphere that transport molecules throughout the cell

smooth endoplasmic reticulum

no ribosomes on surface

• synthesize lipids, metabolize carbs, detox drugs and poison, store Ca 2+

golgi apparatus

synthesis and packaging of materials (small molecules) for transport in vesicles), produces lysosomes, series of flattened membrane sacs (cistenae)

lysosomes

-intracellular digestion- recycle cell’s material; programmed cell death (apoptosis)

cis-face

receives vesicles

phagocytosis

process of bringing “food” into the cell to “eat” , contains hydrolyric enzymes- digests (breakdown of materials)

vacuoles

storage of materials (food, water, minerals, pigments, poisons)

membrane bound - food vacuous, contraction vacuoles

large center vacuole

plant vacuole, stores water, ions, retains water for turgor process

trans- face

shipping vesiciles

endosymbiont theory

the idea that the mitochondria and chloroplasts share similar origins due to similar structure and characteristics

mitochondria

double membrane structure that is the site of cellular respiration in all eukaryotic cells

cristae

folds of inner membrane containing enzymes for ATP production, increased surface area to increase ATP production

matrix 

fluid filled inner compartment of the mitochondria 

chloroplast

double membrane structure that is the site of photosynthesis (only in plant cells)

thylakoids

structure that controls light reactions during photosynthesis; contains chlorophylls and in stacks is known as granum

chlorophylls

pigment for capturing sunlight energy during photosynthesis

peroxisomes 

breaks down fatty acids and detoxes alcohol, produces hydrogen peroxide 

stroma

fluid space in a chloroplast

granum

stack of thylakoid

intramembranous space

space between the inner and outer membrane of the mitochondria

mitochondrial matrix

the inside of the inner membrane

cytoskeleton

network of protein fibers, used for support, motility, regulation of biochemical activities in the cell

microtubules

made from tubulin, largest fibers, shape and supports cell, tracks organelle movement, forms spindle for mitosis and meiosis, component of cilia and flagella

centrosomes

region from which microtubules grow (aka microtubule organizing center)

centriole 

in animals, set of triple microtubules in a ring located in the centrosome

cilia

short and numerous, used for locomotion or movement of fluids

flagella

long and few in quantity, propels through water, 9-2 pattern

microfilaments

protein- actin, smallest fibers, thin solid rods, supporting cell on a smaller scale, cell movement due to pulling forces

myosin

thicker filaments of motor proteins, 2 proteins interact to cause contraction of muscle cells

actin

globular protein

cell walls

protects plants and maintains shape made up of cellulose

large central vacuole 

vacuole specifically for water storage 

extracellular matrix

outside plasma membrane of animal cells; strengthens tissues and transmits external signals to cells

collagen

composed of glycoproteins (mix of sugars and proteins)

plasmodesmata

channels between cells to allow for passage of molecules from cell to cell

tight junctions 

2 cells are fused to form watertight seals 

desmosomes

‘rivets’ that fasten adjacent cells into strong sheets

gap junctions

channels through which ions, sugar, and small molecules can pass