(BIOL 1O1) Module 2: Lesson 6 - Cell Structure and Function//Additional Organelles & Structures

Which is not a component of Cell Theory?

cells can come in both organic & inorganic forms

simplest unit necessary for the activity of all living things

cell

membrane at the boundary of every cell; selective barrier; regulates cell’s chemical composition; materials diffuse across it (ex. oxygen/nutrients in, wastes out)

plasma membrane

Some DNA is held in mitochondria & chloroplasts. (T/F)

True

organized in units called chromosomes

DNA

All cells MUST have:

plasma/cell membrane, cytoplasm, DNA, & ribosomes

Most plant & animal cells are less than ___ microns

Most bacterial cells are less than ___ microns

Plant & animal cells are typically bigger than bacterial cells? (T/F)

100; 10; True

As a cell gets bigger, the ____ of the cell increases faster than the ____ in order to give the cell more contact points for secreting & absorbing material.

volume; surface area

Larger organism = Larger cells. (T/F)

False

Smaller organisms have less cells than larger organisms. (T/F)

True

single cell organisms; do NOT have a nucleus or other organelles except for ribosomes; possess a nucleoid; consist of domains Bacteria & Archaea

prokaryotes

have a nucleus & other membrane bound organelles; all have similair cell structures; can be unicellular or multicellular; consists of plants, animals, protists, fungi

eukaryotes

Every multicellular organism is…

eukaryotic

“bacterial velcro”; allows bacteria to stick/adhere to surfaces

fimbriae

where DNA is concentrated in a region NOT enclosed by a membrane

nucleoid

loose protein synthesis factories; suspended in the cytosol; make soluble proteins; stay in cytoplasm; dissolve in water

free ribosomes

In Eukaryotes, free ribosomes & bound ribosomes can ___

alternate

semifluid portion of the cytoplasm

cytosol

contents of the cell within the plasma membrane; for eukaryotes: the portion inside the cell excluding the nucleus

cytoplasm

consisting of multiple cells

multicellular

consisting of one cell

unicellular

eukaryotes came from prokaryotes; “a big cell acquired smaller cells with excellent skills & kept them”

endosymbiotic theory

contains most of the cell’s genetic info; consists of the nuclear envelope, nuclear pore, chromatin, nucleolus, & ribosomes

nucleus

double membrane surrounding the nucleus; contains nuclear pore complexes & structural proteins (nuclear lamina & matrix)

nuclear envelope

lines inner surface of the nucleus; helps maintain shape

nuclear lamina

extends throughout nuclear interior

nuclear matrix

small holes that allow transport in & out of nucleus; where ribosomes transfer out

nuclear pore

within the nucleus; DNA & protein complex that makes up eukaryotic chromosomes

chromatin

1 very long DNA molecule; made up of highly condensed chromatin

chromosome

within the nucleus; condensed region in the center where ribosomes are made & assembled; stains dark under microscope

nucleolus

small structures that produce proteins; attached to the outside of the ER or nuclear envelope; generally make proteins destined for: insertion into membranes, packaging within organelles, or export from the cell

bound ribosomes

made of RNA & protein; carry out protein synthesis (make proteins); high rate of protein synthesis in the cell = more of them; structue = large subunit + small subunit

ribosomes

collection of membranes inside a eukaryotic cell; all related wither through physical contact or by transfer of membrane vesicles; consists of the plasma membrane, nuclear envelope, endoplasmic reticulum, Golgi apparatus, lysosomes, vesicles, vacuoles

endomembrane system

Which is NOT included in the endomembrane system?

chloroplasts & mitochondria

synthesis & transport of proteins into membranes/organelles or out of the cell

Metabolism & movement of lipids

detoxification of poisons

removed cellular waste

gathering large materials from outside of the cell

roles of the endomembrane system

extensive membrane network in eukaryotic cells; continuous w/ the outer nuclear membrane; accounts for over half of cell membrane material; interior of it is separated from the cytosol & called lumen or cisternal space; function: synthesis & transport of proteins & lipids; 2 types

endoplasmic reticulum (ER)

has ribosomes attached to its surface which make its membrane & secreted proteins; right next to the nucleus; keep secretory proteins & cytosolic proteins separate → secretory proteins leave via vesicles

rough ER (rER)

interior space of the ER; proteins inside can be modified by enzymes here; where polypeptide chains from bound ribosomes thread into & fold in to create secretory proteins

lumen

does NOT have ribosomes attached to its surface; site for lipid (feat. steroids) synthesis, metabolism of carbohydrates, & detoxification of drugs & poisons; amount of it depends on cell function (ex. ovaries produce steroid hormones so ovary cells have more)

smooth ER (sER)

function: packaging & shipping; takes proteins from the ER & gets them ready to be distributed to other destinations; more in cells specialized in secretion

Golgi (Apparatus, Body, Complex)

flat stacks of the membrane that make up the Golgi & ER; membrane of each separates the internal space from the cytosol

cisternae

how materials moved from organelle to organelle; exs. from ER to Golgi, from Golgi to cell membrane for secretion

vesicles

ONLY in animal cells; membranous sac of enzymes; digest macromolecules; acidic, conduct intracellular digestion - digestion into cell (via phagocytosis) or recycle into cell (via autophagy); helps cell renew itself continuously ; digestion products = simple sugars, amino acids, & other monomers

lysosomes

fluid storage sacs in cells; in every eukaryotic cell EXCEPT protists; many small ones in animal cells; single, large one in plants & fungi; many functions depending on cell type; exs. food vacuole, contractile vacuoles

vacuoles

formed by phagocytosis

food vacuoles

expel excess water; ex. in paramecium

contractile vacuoles

for plant cells; absorb water, store ions; plant cells enlarge as these absorb water; provide pressure against the inside of the cell walls; grow with cells

central vacuoles

carry out cellular respiration; common to ALL eukaryotes; convert sugar, fats, & other organic molecules + oxygen into energy for cells; 2 membranes; amount increase with cell’s metabolic activity

mitochondria

carry out photosynthesis; in plants & algae (protist); convert solar energy → chemical energy; sunlight absorbed drives the production of sugars from CO₂ & H₂O; 3 membranes

chloroplasts

“semi-independent” ; grow & reproduce within the cell

semiautonomous

Which eukaryotic organelles are semiautonomous?

chloroplasts & mitochondria

single membrane sac; detoxify alcohol/other harmful substances via transferring H’s to O₂ → enzymes create hydrogen peroxide (cell toxic) → secure hydrogen peroxide to prevent damage until it is converted to H₂O

peroxisomes

network of protein fibers extended throughout cytoplasm; responsible for mechanical, transport + signaling functions, provide support to cell, & aid in cell movement; consists of 3 fibers: microtubules, intermediate filaments, & microfilaments

cytoskeleton

hollow rods; made of tubulin; grow by adding tubulin dimers; one end of it is locked while the other end can grow/shrink; support cell, resist compression, pathway for vesicles + motor proteins carrying organelles

microtubules

globular protein that makes up microtubules; dimer (made up of 2 subunits)

tubulin

in animal cells; used in cell division; ring structures made of 9 sets of triple microtubules

centrioles

Cilia & flagella are…

microtubule extensions that project from some cells

often move substances relative to cell; short length; can move single cells

cilia

move the cell itself; long length

flagella

solid rods; linear chain of actin subunits; bear tension/pulling forces

microfilaments

globular protein that makes up microfilaments

actin

motor protein that binds to actin in microfilaments; drives muscle contractions

myosin

common in animal cells; between microtubules & microfilaments; bear tension; each constructed from different protein family subunits (ex. keratin); more permanently fixed/stable → do NOT grow/ shrink; ex. nuclear lamina

intermediate filaments

protective external layer to the plasma membrane of plants, prokaryotes, fungi, & some
protists; made of polysaccharides: cellulose (plants, protist), chitin (fungi), peptidoglycan (bacteria)

cell wall

animals have this instead of a cell wall; provides a substrate for cells to adhere to

extracellular matrix

membrane-lined channels filled with cytoplasm connecting adjacent plant cells; allow communication & coordination between cells; can move water, ions, + small molecules between cells

plasmodesmata

bind the adjacent cells together via interaction of trans-membrane proteins; prevent fluid from moving between cells

tight junctions

anchor cells together; intermediate filaments bind to them

desmosomes

channels between adjacent cells; allow water, ions, and small molecules to move between cells

gap junctions

Tight junctions, gap junctions, & desmosomes are all solely for…

animal cells