2 Big Idea 4: Biological systems interact, and these systems and their interactions possess complex properties.EU 4.A: Interactions within biological systems lead to complex properties. EU 4.B: Competition and cooperation are important aspects of biological systems. EU 4.C: Naturally occurring diversity among and between components within biological systems affects interactions with the environment.
3 EK 4.A.2: The structure and function of subcellular components, and their interactions, provide essential cellular processes.RibosomesEndoplasmic Reticulum (see 2.b.3)Golgi Complex (see 2.b.3Mitochondria (see 2.b.3)LysosomesVacuolesPeroxisomesNucleus (see 2.b.3)Chloroplasts (see 2.b.3)Cell WallCytoskeletonECMIntercellular JunctionsStop
4 Ribosomes Nonmembrane, universal structures Comprised of two interacting parts: ribosomal RNA and protein.Site of protein synthesisWhere the translation of the genetic instructions yields specific polypeptides.
5 Lysosomes Membrane-enclosed sacs produced by Golgi apparatus Functions Intracellular digestionRecycling of a cell’s organic materialsProgrammed cell death (apoptosis).Contain hydrolytic digestive enzymes.Enzymes work best at low pH (5)Membrane pumps in H+Isolates digestion.Macrophages use lysosomes to digest bacteria.
6 Lysosomes Autophagy When lysosomes digest parts of cells Important during development (e.g., tadpole tail absorption, degeneration of webbing between human fingers).Missing or inactive lysosomal enzymes cause serious childhood diseases.Pompe’s disease- missing carbohydrase, glycogen accumulates, damages liver.Tay-Sachs disease- missing lipase, lipids accumulate in brain.
7 VacuolesA membrane-bound sac that plays roles in intracellular digestion and the release of cellular waste products.In plants, a large central vacuole serves many functionsStorage of pigments or poisonous substancesCell growth and supportAlllows for a large surface area to volume ratio.Membrane is called the tonoplastTypes include: food, digestive, and in some protists, water-regulating contractile vacuoles.
8 Peroxisomes Abundant in liver Not from endomembrane. From cytosol proteins and lipids.Transfers hydrogen (from substrates) to oxygen forming hydrogen peroxide(H2O2).Also occur in germinating seeds (glyoxysomes) where they convert oils into sugars
9 Cell WallMainly cellulose fibers in a matrix of polysaccharides and proteins.Protect plant cellsPrevent water loss.Maintain cell shape
10 Cytoskeleton Mechanical support and helps maintain shape. Elements can disassemble and reassemble in life of a cell.Three Types of FibersMicrotubulesMicrofilamentsIntermediate filaments
11 Microtubules Hollow cylinders 25 nm in diameter Composed of -tubulin and -tubulin dimersFunctionsHelp maintain shape of cells.Act as tracks along which organelles move.Motor molecules kinesin and dynein are associated with microtubules.Motor molecules change shape with ATP.Move chromosomes.Make up centrioles in animal cells.
12 Microtubules Cilia and Flagella Cilia are short, usually numerous hairlike projections.Flagella are longer, usually fewer, whip-like projections.Composed of a pattern of microtubules.
13 MicrofilamentsTwo chains of actin protein monomers twisted to form a helix.7 nm in diameterFunctionsForms a dense complex web just under the plasma membrane.Form microvilli of intestinal cellsIn plant cells, they form tracts along which chloroplasts circulate.Interaction with myosinFor muscle contractionFor pinching off cells during cell divisionFor amoeboid movement.
14 Intermediate Filaments Rope-like assemblies of fibrous keratin8-12 nm in diameterMore permanent than microtubules and microfilaments.FunctionsSupport nuclear envelope and plasma membraneForm cell-to-cell junctions.
15 Extracellular Matrix (ECM) Mesh of macromolecules outside plasma membrane of animal cells.Composed mainly of glycoproteins (collagen)- ½ of total protein in vertebrates.Provides support and anchorage for cells.
16 Intercellular Junctions Plants have PlasmodesmataAnimal CellsTight Junctions- Block transport of substances between cells.Desmosomes- Rivet cells together, but still permit transport of substances.Gap Junctions- Two connecting protein rings in adjacent cells.
17 Endoplasmic Reticulum Continuous with outer membrane of the nuclear envelope.Most extensive portion of endomembrane system.Rough endoplasmic reticulumServes as mechanical supportProvides site-specific protein synthesis with membrane-bound ribosomesIntracellular transport of protein.Makes secretory proteins (mainly glycoprotiens)Packages proteins as transport vesicles.Makes new membranes.
18 Endoplasmic Reticulum Smooth ER (no ribosomes)Synthesizes lipids, phospholipids, and steroidsIn LiverConverts glycogen to glucose to regulate blood sugar.Detoxifies drugs and poisons (adds hydroxyl groups making them water soluble).Stores Ca+ in muscle
19 Golgi Complex Membrane-bound structure Consists of a series of flattened membrane sacs (cisternae).Synthesis and packaging of materials (small molecules) for transport (in vesicles)Receives protein-filled vesicles that bud from the ER at cis face.Proteins are modified and repackaged as new vesicles.Vesicles leave from trans face.At plasma membrane, they discharge their contents as secretions.Produces lysosomes.
20 Mitochondria Have a double membrane that allows compartmentalization Inner membrane is highly convoluted, forming folds called cristae.Cristae contain enzymes important to ATP productionCristae also increase the surface area for ATP productionSites of cellular respiration.Contain ribosomes and their own DNASpecialize in energy capture and transformation.
21 NucleusNuclear envelope: a double membrane that separates nucleoplasm from cytoplasm.Stores genetic information determining structure/function of cellsSite where nucleic acids are synthesizedChromatin: Fine strands of DNA and protein (histones)Chromosomes: rod-like structures formed during cell division from coiled or folded chromatin.(46 in humans)
22 Nucleus Nucleoplasm Semifluid medium of nucleus Has a different pH from cytosolNucleolus: sites where rRNA joins proteins to form ribosomes.Nuclear pores (100 nm)- permit passage of certain mRNA and ribosomes
23 ChloroplastsSpecialized organelles found in algae and higher plants that capture energy through photosynthesis.Capture the energy available in sunlight and convert it to chemical bond energy via photosynthesis.Contain ChlorophyllsResponsible for the green color of a plantThe key light-trapping molecules in photosynthesis.There are several types of chlorophyll, but the predominant form in plants is chlorophyll a.
24 ChloroplastsHave a double outer membrane that creates a compartmentalized structureContain membrane-bound structures called thylakoids.Thylakoids are organized in stacks, called granaEnergy-capturing reactionsProduce ATP and NADPHWhich fuel carbon-fixing reactions in the Calvin-Benson cycleCarbon fixation occurs in the stromaWhere molecules of CO2 are converted to carbohydrates.
25 Chloroplasts Chloroplasts are a type of plastid. Amyloplasts store starch (amylose, amylopectin)Chromoplasts, which contain red and orange pigments.Only plants, algae, and cyanobacteria carry on photosynthesis.There are no chloroplasts in cyanobacteria; chlorophyll is bound to cytoplasmic thylakoids.
26 Cell Theory Cell is the smallest unit of life Robert Hook (English) st to observe/name cells (cork,dead)Anton Van Leeuwenhoek (Dutch) st to observe live microorganismsAll Organisms are composed of CellsMatthias Schleiden (botanist), 1838Theodor Schwann (zoologist), 1839Cells come from cellsRudolf VirchowPhysician, 1855