APBIO- Cells and Organelles

cell membrane

fluid, mosaic membrane which surrounds the cell. Regulates transport in and out of the cell.

cell wall

only found in plant cells, provides structure and rigidity

middle lamella

pectin rich layer which holds adjacent plant cells together

plasmodesmata

channels between cell walls which allow transport of water and nutrients and communication between cells. 

vacuole

vesicle withing cytoplasm in eukaryotic cells which holds water and nutrients and regulates waste products.

central vacuole

can make up 90% of a plant cell, maintains turgor pressure and stores nutrients.

nucleus

brain of the cell. holds DNA and controls growth and reproduction

nucleolus

small structure within the nucleus that creates ribosomes. it has no membrane

Golgi apparatus

modifies, sorts, and packs proteins and lipids for secretion or delivery

folded membranous sacs organized into cisface size which receives proteins from the rough ER, and the transface which sends proteins out. 

endoplasmic reticulum

membranous tubes within cytoplasm. synthesize, fold, modify, and transport proteins and lipids.

rough ER

studded with ribosomes, surrounds the nucleus. handles protein production. 

smooth ER

responsible for lipid synthesis, carb metabolism, and detoxification

ribosomes

read mRNA and synthesize proteins. found in rough ER or the cytoplasm.

lysosome

breaks down waste materials, dead cells, and invaders. Recycling center of the cell.

mitochondria

powerhouse of the cell. generate ATP through cellular respiration. have their own DNA

plastid

organelles in plant cells responsible for photosynthesis (chloroplast), food storage (chromoplasts), and hold starch/oils/proteins (leucoplasts). 

double membrane

chloroplast

green organelles in plant cells which facilitate photosynthesis to form glucose.

stroma

fluid-filled space within chloroplast surrounding thylakoids. site of photosynthesis

thylakoids

interconnected, flattened membrane-bound sac where light-dependent reactions occur within chloroplast. contain chlorophyll. 

granum

stack of thylakoids.

cytoplasm

gel-like substance which fills the cell. where most chemical reactions take place. holds organelles in place and facilitates movement within the cell.

centriole

cylindrical organelle which helps divide cells. base of cilia and flagellum. only in animal cells

cytoskeleton

network of protein fibers. provide structure, maintain shape, and enable cell movement. composed of microtubules and microfilaments (actin).

nuclear pore

protein-lined channel which regulates transport between the nucleus and cytoplasm

peroxisome

single-membrane bound. carries out lipid metabolism and detoxification of reactive oxygen. located in the chloroplast. contains catalase.

amyloplast

starch filled sac. found in pulp cell of potato

lumen

empty cavity within a cell

centrosome

contains centrioles. spindle fibers grow out of it during cell division.

vesicle

small sac which transports substances within the cell

chromatin

strands of DNA found within the nucleus of eukaryotic cells, or DNA plastid in prokaryotes.

cisternae

flattened, membrane-bound sacs which make up the Golgi apparatus and ER

lignin

complex polymer within the cell wall making them more rigid

pectin

provides support to cell wall (middle lamella)

eubacteria

common prokaryotic bacteria

archaebacteria

uncommon prokaryotic bacteria, found in extreme environments. monolayer membrane

peptidoglycan

found in cell wall of eubacteria to provide structural support. barrier against turgor pressure

Gram +

thick layer of peptidoglycan in cell wall. appear purple under gram stain test. (eubacteria)

Gram -

thin peptidoglycan layer and additional outer membrane. appear pink under gram stain (eubacteria)

Krebs cycle

aerobic respiration within cytoplasm of eubacteria. 

glycolysis

breakdown of glucose by enzymes (eubacteria)

methanogen

methane producing bacteria. reduce carbon dioxide to methane. (archaebacteria)

introns

non-coding section of DNA which is transcribed into RNA but removed before being translated into a protein. (archaebacteria)

cyanobacteria

photosynthetic bacteria which live in the oceans and freshwater.

pathogen

microorganism which can cause disease (eubacteria)

flagella

hair-like appendage which enable movement in organisms. 9+2 microtubule arrangement

pilli

hair-like protein filament of surface on bacteria which help with adhesion and genetic trasnfer

plasmid

small, circular, double-stranded DNA separate from chromosomal DNA. found in cytoplasm.  can carry antibiotic resistance.

nucleoid region

region where circle DNA molecule is located. not enclosed by a membrane

prokaryotic

single-celled organism which doesn’t have a distinct nucleus or specialized organelles

endosymbiosis

biological relationship in which one species live inside another. mainly parasitic relationships. 

mutualistic endosymbiosis

mutual relationships between two species. eg. giant green sea anemone and algae that live within its tissues. Anemones receive sugar produced by the algae through photosynthesis and the algae get a safe place to live.

cellular compartmentalization

divides internal volume of cell into compartments which have distinct properties and functions. 

endomembrane system

network of organelles in eukaryotic cells which take part in protein synthesis