Cells

Front 1

Modern Cell Theory

Back 1

-all living things are composed of cells
-cells are the basic unit of all organisms
-all cells arise from preexisting cells

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prokaryote

Back 2

very small (1-10 μm)
no nucleus, internal membranes, or cytoskeleton
circular, naked DNA
very small ribsomes
an/aerobic metabolism
mainly unicellular
all bacteria are prokaryotes

Front 3

eukaryote

Back 3

distinct organelles
DNA wrapped with histone proteins into chromosomes
aerobic metabolism
cytoskeleton present
multicellular, differentiated cells
10-100 μm

Front 4

methods of cell study

Back 4

cell fractionation
freeze fracture or freeze-etching
tissue culture

Front 5

nucleus

Back 5

contains chromosomes
wrapped with special proteins into a chromatin network
selectively permeable nuclear membrane or envelope that contains pores for transport

Front 6

nucleolus

Back 6

in the nucleus of a cell during interphase
where ribosomes are synthesized
not membrane-bound

Front 7

ribosomes

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protein synthesis
free in the cytoplasm or attached to the ER

Front 8

endoplasmic reticulum (ER)

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ROUGH- where ribosomes are attached ➭ protein synthesis
SMOOTH- synthesis of steroid hormones and other lipids, connects rough ER to the Golgi apparatus, detox

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Golgi apparatus

Back 9

near the nucleus
flattened membranous sacs surrounded by vesicles
packages substances produced in the rough ER and secrete them to other cell parts

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lysosome

Back 10

sacs of hydrolytic enzymes surrounded by a single membrane
principal site of intracellular digestion
the method by which cells renew themselves (by breaking down and recycling cells)
aids in apoptosis (programmed cell death)
not found in plant cells

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peroxisome

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found in both plant and animal cells
contains catalase, which converts hydrogen peroxide H2O2 (waste product of respiration)

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mitochondrion

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cellular respiration
found in all cells
outer double membrane and inner membranes called cristae (maximizes surface area)
has own DNA

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vacuole

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single, membrane-bound storage structure
vesicles - tiny vacuoles

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plastid

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double membrane
only in plants and algae
3 types (chloroplasts, leucoplasts-store starch, chromoplasts-store carotenoid pigments)

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chloroplast

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photosynthesis
double outer membrane
has own DNA
inner system of structures called grana (consisting of thylakoids)
grana lie in the the stroma

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cytoskeleton

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complex network of protein filaments throughout the cytoplasm
gives shape, enablesmotion, anchors organelles to the plasma membrane
consists of microtubules and microfilaments

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microtubules

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hollow tubes made of tubulin
make up cilia, flagella, and spindle fibers
9 pairs around 2 single microtubules

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microfilaments

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(actin filaments)
support the shape of a cell
enable cleave furrow, pseudopods, skeletal muscle contraction as they slide myosin filaments

Front 19

cell wall

Back 19

in plants and algae, made of cellulose; in fungi, made of chitin; in prokaryotes, made of polysaccharides and complex polymers
primary cell wall right outside the plasma membrane
secondary cell wall outside the primary cell wall
middle lamella- thin gluey layer between two cells after division

Front 20

cell or plasma membrane

Back 20

selectively permeable membrane
S.J. Singer credited with fluid-mosaic model
(eukaryotic) consists of amphipathicphospholipid bilayer, integral proteins, peripheral proteins, cholesterol molecules, glycocalyx, protein channels

Front 21

functions of plasma membrane

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transport
enzymatic properties
receptors for substances (ie hormones, neurotransmitters)
cell to cell attachments (desmosomes)