Chapter 3: Cellular Form and Function (Class)
- Internal structures of a cell that carry out specialized metabolic tasks.
- Has membranous organelles (Bound to the membrane) and organelles that are not membrane bound
- Are surrounded by one or two layers of unit membrane.
- Includes: nucleus, mitochondria, lysosomes, peroxiosomes, endoplasmic reticulum (smooth and rough), Golgi complex, Phagosome
Membranous organelles
- not surrounded by membranes
- Includes: nucleolus, ribosomes, centrioles, centrosome, basal bodies, intermediate filaments, microfilaments and microtubules (both parts of cytoskeleton)
Non-membrane bound organelles
- Double biphospholipid membrane
- Contains: Nucleoplasm, Nucleolus, Nuclear pores, Double Biphospholipid membrane, Most DNA (Chromosomes)
- Two unit membrane surrounding nucleus
- Perforated with nuclear pores (formed protein rings)
Nuclear Envelope (Nucleus)
- Regulate molecular traffic and hold the two membranes together
- What comes in:
*Raw materials for DNA and RNA synthesis
*Enzymes made in cytoplasm but function in nucleus
*Hormones that activate certain genes
- What leaves:
*RNA made in nucleus but performs job in cytoplasm
Nuclear Pores (Nucleus)
*Eurochromatin: expanded out, can be copied to transfer info
*Heterochromatin: closely bunched up. Does not work
Chromatin (Nucleus)
Nucleoli (singular), Nucleolus (plural)
- Fine thread-like matter composed of DNA, Histone protein and one or more dark-staining masses of nucleoli and attached to laninin on the walls
Nucleoli (Nucleus)
- system of interconnected channels (cisternae)
- consists of Rough ER and Smooth ER
- Synthesizes steroids and other lipids, detoxifies alcohol and other drugs, and manufactures all membranes of the cell
Endoplasmic Reticulum
-Continuous w/ outer membrane of nuclear envelope.
-Produces secreted proteins (proteins that are dangerous for the cell that proceed to golgi complex for more work (ex: antibody producing cells)
Rough ER (ER)
-Produces lipids (no ribosomes)
-Engaged in detoxification (ex:liver and kidneys)
-Synthesis of steroid hormones (ex:testes and ovaries)
-Storage of calcium to trigger muscle contraction
Smooth ER (ER)
- Small granules of protein and RNA
- Found in nucleoli, cytosol, outer surface of rough ER and nuclear envelope
-reads mRNA and assemble amino acids into proteins specified by code
-unattached ribosomes in cytoplasm make enzymes and proteins for use within cell
-attached ribosomes (to rough ER) make proteins for lysosomes to be secreted from cell
-small system of cisternae that synthesize carbs and puts finishing touches on protein and glycoprotein synthesis.
-receives newly synthesized proteins from rough ER; sorts, cuts and splices some of them; adds carb(sugar) moieties to some; packs in golgi vesicles and buds off ends of cisternae (ex: lysosomes)
Golgi Complex
-produced in golgi complex
-package of enzymes w/ single unit membrane
*multi-types; mainly DNASE, RNASE, PROTEASE, LIPASE: all pH dependent. cannot function unless environment is acidic: H+ ATPase (proton pump) creates low pH
-hydrolyze proteins, nucleic acids, complex carbs, phospholipids etc.
-"Cell suicide" - some cells are meant to do a certain job then destroy self
-Digestion of surplus cells by their own lysosomal enzymes
Autolysis (Lysosome)
-resemble lysosomes, but created in ER and contain different enzymes
-decompose fatty acids into two-carbon fragments that the mitochodria use as an energy source for ATP synthesis
1.uses molecular oxygen (O2) to oxidize organic molecules
2.produce hydrogen peroxide (H2O2)
3.H2O2 used to oxidize other molecules and excess is broken down to H2O by catalase enzyme
4.neutralize free radicals and detoxify alcohol, drugs and blood-borne toxins
-CO2 created here
-double biphosopholid membrane
-specialized for synthesizing ATP
-krebs cycle
*energy NOT MADE; extracted from organic compounds and transfered to ATP by enzymes in cristae
matrix has OWN ribosomes, mitochondrial circular DNA, enzymes for ATP
-a series of chemical reactions used by all aerobic (oxygen needing) organisms to generate energy through the oxidization of acetate derived from carbs, fats and proteins into carbon dioxide and water.
-Allows H+ to enter mitochondria and into the matrix (electron transport chain)
Krebs Cycle/Citric Acid Cycle (Mitochondria)
-The energy to convert glucose to pyruvate (3 carbon chain)
-Uses 2 ATP to split the 6 carbon chain into three carbon chains
-Takes electron->pyruvate->lactic acid
-Anerobic: does not need oxygen to function
-3 carbon chain
-made by splitting glucose in half
-play a role in cell division
-centrosome: two centrioles lie perpendicular to each other n a small clear area of cytoplasm
-Cilium and Flagellum basal bodies: a single centriole oriented perpendicular to plama membrane
-Type of Smooth ER that stores calcium
ex: bones, muscles (no protoplasm)