Organelles Quiz

DNA Structure

46 human chromosomes DNA is wrapped around proteins (called chromatin), proteins act like magnets and hold DNA together in clumps (like beads on a string), one big clump is a chromosome

Prokaryotic Cells

Capsule, cell wall made of peptidoglycan, flagella made of flagellin, cytoplasm, DNA, plasma membrane, ribosomes, cytoskeleton, no vesicles, no Golgi apparatus, no E.R., no nucleus, no mitochondria, no centriole, no lysosome, no vacuoles, no chloroplasts, no cilia, (no membrane bound organelles)

Plant Cells

Cell wall, chloroplasts, central vacuole, nucleus, ribosomes, mitochondria, Golgi apparatus, E.R., plasma membrane, DNA, cytoskeleton, peroxisomes, flagella, cytoplasm, no lysosomes, no centrioles, no cilia

Eukaryotic Cells

Flagella made of microtubules, cell wall made of cellulose, vesicles, Golgi apparatus, E.R., nucleus, mitochondria, centriole, centrisome, lysosome, vacuoles, chloroplast, cilia, no capsule, cytoplasm, DNA, plasma membrane, ribosomes, cytoskeleton (membrane bound organelles) Larger because have more organelles (10x larger)

Cell Size

Lower limit: must have enough DNA and enzymes to support itself Upper limit: must have a surface area to volume ratio that allows for quick transport - microvilli: long, thin projections that increase surface area

Protein Making

Start in nucleus, DNA makes RNA, RNA tells ribosomes in rough ER to make protein, protein gets in vesicle made from membrane of nucleus and goes to Golgi apparatus where it is modified put in another vesicle and sent to membrane of cell and pushed out

Cell Wall

Structure: Plants = cellulose embedded in a matrix of other carbs and proteins. (made by cellulose synthase). Prokaryote = peptidoglycan. Thicker than cell membranes. Young plants have a primary cell wall (between the primary cell walls of plants is the middle lamella: a thin layer rich in sticky polysaccharides called pectins - glues cells). Plant matures, strengthens wall either by secreting a hardening substance or adding a secondary cell wall Function: protects plant cell, maintains its shape, prevents lysing, hold plant up against the force of gravity. Cells: Plant and Prokaryote

Cytoplasm

Structure: Water, salts, enzymes Function: All organelles in, maintain salinity and pH Cells: All cells

All Cells

Cytoplasm, plasma membrane, DNA, ribosomes

Lysosome

Structure: membranous sac of hydrolytic enzymes that cells use to digest macromolecules. acidic environment. made by rough ER transferred to golgi Function: digestion in a cell, autophagy: recycle own organic material from damaged organelles in vesicles that bind to lysosomes. Food vacuoles bind to lysosomes for digestion Cells: Animal cells

Cytoskeleton

Function: gives mechanical structure to the cell and maintains its shape. stabilized by a balance between opposing forces exerted on it. Provides anchorage to organelles and enzymes in cytosol. can be disassembled and reassembled to change the shape of the cell. cell motility: change in cell location and movement of cell parts: interactions between motor proteins and the cytoskeleton

Size of Tubules and Filaments (Big -> Small)

Microtubules -> Intermediate Filaments -> Microfilaments

Animal Cells

No cell wall, round/irregular shape, one or more small vacuoles, centriole, no chloroplasts, cytoplasm, ER, ribosomes, mitochondria, Golgi apparatus, plasma membrane, lysosomes, nucleus, cilia, peroxisomes, cytoskeleton, flagella, DNA

Cell Junctions

Plasmodesmata: in plant cells, cytosol passing through connects internal chemical environment - unify most of the plant into one continuum, plasma membranes line that channels and are continuous. Tight Junctions: animal cells, plasma membrane are tightly bound together by specific proteins, make skin waterproof - prevent extracellular fluid from moving through a layer of cells Desmosomes: fasten cells into strong sheets, anchored into cytoplasm by intermediate filaments, attach muscle cells Gap Junctions: cytoplasmic streaming channels from cell to cell -- membrane proteins surround a pore that small molecules can move through

Extracellular Matrix

Structure: glycoproteins and other carb-containing molecules. Mostly collagen: forms strong fibers outside the cell. Collagen fibers embedded in proteoglycan network: small core proteins with many carb chains. Proteoglycan complex: many IMF with a long polysaccharide. Fibronectin: attaches cells to ECM bind to integrins in membrane that span membrane and connect to microfilaments transmit signals from ECM to cytoskeleton Function: ECM can regulate cell behavior, influence gene activity

Plasma Membrane

Structure: Bilayer of phospholipids Function: Holds cytoplasm in, selective barrier Cells: All cells

Peroxisome

Structure: Bound by a single membrane, contains enzymes. Function: Remove H from various substrates and transfers them to O2 creating H2O2 and converts that to H2O. Breaks down fatty acids for fuel Glyoxisomes: specialized peroxisome found in fat storing tissue of plant seeds initiate conversion of fat to sugar Cells: Eukaryotic

Vesicle

Structure: Bubble of membrane with fluid and a macromolecule inside Function: Carry molecules through membranes, transport vehicle Cells: Eukaryotic

Intermediate Filaments

Structure: Can vary in diameter and composition. Made of subunits of proteins from a particular family that includes keratin Function: Bear tension. More permanent fixtures. Are not disassembled and reassembled so they are especially sturdy, reinforce shape of cell and position of organelles. Only found in some animal cells

Capsule

Structure: Carbohydrates Function: Make cell sticky, so it can stick Cells: Prokaryote

Ribosome

Structure: Complexes made of rRNA and proteins Function: carry out proteins synthesis. Free ribosomes are in cytosol and make proteins for the cell. ER ribosomes are attached to the ER and make proteins for transport. Cells: All cells but prokaryotes' are floating and eukaryotes are either floating or in the E.R

Microtubules

Structure: Hollow rods constructed from tubulin. Tubulin is a dimer (alpha and beta subunits). This causes the MT to have two different ends, one end can grow and shrink must faster (plus end) Function: Shape and support the cell, serve as tracks along which organelles can move. Compression resisting. Grow out of centrosome

Vacuoles

Structure: Membrane, water, amino acids, made in ER and golgi Contractile vacuoles: pump excess water out of cell, maintaining suitable concentration of ions and molecules, move unicellular Central vacuole: plant cells, solution inside called cell sap: plants main reserve of inorganic ions, enlarge as water comes in, allows less cytosol to be needed Cells: Plant = one, 40%-90% of cell, Animal = multiple

DNA

Structure: Nitrogenous base, dioxyribose sugar, phosphate Function: Encode genetic instructions to make proteins Cells: All cells

Chloroplasts

Structure: Outer and inner membranes with stacks of membranes inside (thylakoid), near edge of cell to get sunlight, own DNA Thylakoids: flattened inner-connected sacs inside chloroplasts. In stacks called granum. Stroma: fluid outside thylakoids, contains cDNA, ribosomes, and enzymes Can change shape, grow, and divide Part of a family of organelles called plastids Function: Convert solar energy to cellular energy and synthesize organic compounds from carbon dioxide and water

Flagella

Structure: Prokaryotes = flagellin, fixed with rotating base, Eukaryote = microtubules, connected to centriole, 9 doublets of microtubules with doublet in center, surrounded by membrane, swing Function: Move entire cell Cells: Prokaryotes, animals and plants

Cilia

Structure: Same structure as flagella, cover entire outside of cell Function: Move things along cells, like mucus (oar motion) Primary cilium: signal receiving antenna, crucial to brain function and embryonic development Cells: Protists, animals (animals won't have cilia and flagella)

Microfilaments

Structure: Thin solid rods made of actin. Twisted double-chain of actin subunits. Can be branched networks. Function: Bear tension. Cortical microfilaments: network of MF just inside membrane that help support the cell shape. This gives the cytoplasm just under the membrane a semisolid consistency Interactions between MF and myosin filaments cause muscle contraction, crawling of amoeba, and cytoplasmic streaming

Nucleus

Structure: enclosed by nuclear envelope - double membrane perforated by pores that are lined by pore complex: protein structure that regulates pore. Nuclear side of the envelope is lined by the nuclear lamina: a netlike array of protein filaments that maintain the shape of the nucleus, could help organize genetic material. DNA is organized into chromosomes Function: Holds genetic information Cells: Eukaryotic

Golgi Apparatus

Structure: flattened membrane sacs called cisternae. Distinct directionality: cis (receiving) and trans (shipping) faces, membranes on either side differ in thickness and composition Function: Modifies, sorts, packages proteins for secretion or use, directs destination by adding tags (phosphate groups) and adding external molecules to vesicles to recognize docking sites. Cisternal Maturation Model: cisternae progress foward from cis to trans carrying and modifying as they go Cells: Eukaryotic

Centrosome

Structure: made of two centrioles. composed of nine sets of triplet microtubules arranged in a ring Function: Make cell division more efficient, make spindle fibers to separate chromosomes, build microtubules Cells: Only animals

ER

Structure: network of membranous tubules and sacs called cisternae. Internal compartment = ER lumen, continuous with the nuclear envelope. Smooth ER: no ribosomes, enzymes to make lipids Function: make lipids (steroids, oil, phospholipids), detoxify drugs and poisons by adding OH group, stores Ca ions for muscle contraction Rough ER: Bounded ribosomes Function: proteins formed by bound ribosomes are threaded into ER lumen that leave ER in vesicles. Grows in place by adding membrane proteins and phospholipids to its own membrane. Cells: Eukaryotic, surrounds nucleus,

Mitochondria

Structure: smooth outer membrane, inner membrane with folds called cristae (increase surface area). Divided into two spaces - intermembrane space between outer and inner membrane space and the mitochondrial matrix inside the inner. Matrix contains enzymes, mDNA, and ribosomes. Move around, change shape, fuse and divide. Also form a branched network. Function: Produce ATP from glucose, powerhouse of cell, makes energy Cells: Plants and animals, higher concentration in cells that work harder (heart and muscles)

Nucleoulus

densely stained granules and fibers where rRNA is synthesized and proteins from the cytoplasm are assembled with rRNA to form ribosome subunits