A typical animal cell -Contains a variety of membranous organelles; may have flagella, Rough endoplasmic reticulum Smooth endoplasmic reticulum Nucleus Flagellum Not in most plant cells Lysosome Centriole Peroxisome Golgi apparatus Ribosomes Microtubule Cytoskeleton Intermediate filament Mitochondrion Plasma membrane Microfilament A typical plant cell has some structures that an animal cell lacks Such as chloroplasts and a rigid cell wall (cellulose) Uusually have a central vacuole, lack centrioles, and usually lack lysosomes and flagella. The origin of chloroplasts Nucleus Golgi apparatus Rough endoplasmic reticulum Ribosomes Smooth endoplasmic reticulum Microtubule Not in animal cells Central vacuole Chloroplast Cell wall Intermediate filament Microfilament Cytoskeleton Mitochondrion Peroxisome Plasma membrane Figure 4.4B
A typical plant cell has some structures that an animal cell lacks Such as chloroplasts and a rigid cell wall (cellulose) Uusually have a central vacuole and chloroplasts, lack centrioles, and usually lack lysosomes and flagella. The origin of chloroplasts Nucleus Golgi apparatus Rough endoplasmic reticulum Ribosomes Smooth endoplasmic reticulum Microtubule Not in animal cells Central vacuole Chloroplast Cell wall Intermediate filament Microfilament Cytoskeleton Mitochondrion Peroxisome Plasma membrane Figure 4.4B DNA is on these Chromatin Fibers which are Chromosomes (2 m long if uncondensed)
(rrna) is transcribed and assembled within the nucleolus; rrna is a facilitator in during protein synthesis by ribosomes Building blocks of ribosomes made here and exit via pores Messenger RNA made in nucleus and travels through pores to ribosomes with information (code) on proteins to make
Centrosomes -make micro tubules -pull chromosomes to dividing cell -located outer nucleus membrane -self-duplicate -may contain DNA Overview: Many cell organelles are connected through the endomembrane system A. An extensive system of membranous organelles, referred to as the endomembrane system, work together in the synthesis, storage, and export of molecules. B. Each of these organelles is bounded by a single membrane. Some are in the form of flattened sacs; some are rounded sacs; and some are tube-shaped. C. The major function of the endomembrane system is to divide the cell into separate compartments like an automobile assembly plant
Rough endoplasmic reticulum makes membrane and proteins Rough endoplasmic reticulum (rough ER) is composed of flattened sacs that often extend throughout the entire cytoplasm. The rough ER has three functions: synthesis, modification, and packaging of proteins. Ribosomes on the surface of rough ER make proteins, some of which are incorporated into the membrane. Other proteins are packaged in membranous sacs that bud off the rough ER and are transported to the Golgi apparatus Ribosome Transport vesicle buds off 4 1 3 Secretory (glyco-) protein inside transport vesicle Sugar chain Polypeptide 2 Glycoprotein Rough ER The genetic code is degenerate. With the exception of Methionine and Tryptophan, every amino acid is coded by more than one codon Anti-codons codon Large and small subunits contains ribosomal RNA (rrna) and more than 50 proteins
The genetic code is degenerate. With the exception of Methionine and Tryptophan, every amino acid is coded by more than one codon Anti-codons codon Large and small subunits contains ribosomal RNA (rrna) and more than 50 proteins The Golgi apparatus finishes, sorts, and ships cell products Stacks of membranous sacs receive and modify ER products Transport vesicles from the ER fuse on one end of a Golgi apparatus to form flattened sacs These sacs move through the stack like a pile of pancakes added at one end and eaten from the other. Molecular processing occurs in the sacs as they move through the Golgi. At the far end, modified molecules are released in transport vesicles. Receiving side of Golgi apparatus Transport vesicle from ER New vesicle forming Shipping side of Golgi apparatus Golgi apparatus Transport vesicle from the Golgi Golgi apparatus TEM 130,000?
Smooth endoplasmic reticulum has a variety of functions Smooth endoplasmic reticulum, or smooth ER Lacks surface ribosomes Synthesizes lipids Processes toxins and drugs in liver cells Stores and releases calcium ions in muscle cells Smooth ER Rough ER Nuclear envelope Ribosomes Smooth ER Rough ER TEM 45,000? Smooth endoplasmic reticulum has a variety of functions Smooth endoplasmic reticulum, or smooth ER Lacks surface ribosomes Synthesizes lipids Processes toxins and drugs in liver cells Stores and releases calcium ions in muscle cells Smooth ER Rough ER The synthesis of lipids and metabolism of toxins and drugs is enzyme mediated and of course enzymes are proteins which in turn are coded in DNA Smooth ER Nuclear envelope Ribosomes Rough ER TEM 45,000?
Lysosomes are digestive compartments within a cell Lysosomes are sacs of enzymes (proteins coded ) Lysosome vesicles contain hydrolytic enzymes that break down the contents of other vesicles, damaged organelles, or bacteria with which they fuse. Lysosomes are the recycling center for the cell. Rough ER 1 Transport vesicle (containing inactive hydrolytic enzymes) Plasma membrane Golgi apparatus Engulfment 2 Lysosome engulfing of particle damaged Food organelle 3 Lysosomes Food vacuole 4 Digestion 5 Lysosomes also recycle damaged organelles Peroxisomes - remove oxidants have anti-oxidant function Internal and external oxidants (free radicals) cause hundreds of disorders and diseases. Oxidants contain single unpaired electrons looking for electrons to pair with.
A review of the endomembrane system The various organelles of the endomembrane system Are interconnected structurally and functionally Vesicles can fuse with the plasma membrane and deliver the content to the extracellular environment without the content actually crossing the plasma membrane. Rough ER Transport vesicle from ER to Golgi Transport vesicle from Golgi to plasma membrane Plasma membrane Nucleus Transport vessicles Lysosome Smooth ER Nuclear envelope Golgi apparatus Vacuoles function in the general maintenance of the cell Plant cells contain a large central vacuole that function in storage, play roles in plant cell growth, maintain turgor pressure, and may function as large lysosomes. The vacuoles may also contain pigments or poisons.. Nucleus Chloroplast Central vacuole Colorized TEM 8,700?
ENERGY-CONVERTING ORGANELLES Chloroplasts convert solar energy to chemical energy Chloroplasts, found in plants and some protists And symbiotic algae living in live corals and sea anenomes Chloroplasts are double-membrane-bounded. Convert solar energy to chemical energy in sugars, the site of photosynthesis The capturing of light and electron energizing occur on the stacks or granum (plural, grana), and chemical reactions that form food-storage molecules occur in the stroma. Chloroplast Stroma Inner and outer membranes Granum TEM 9,750? Intermembrane space (light reax takes place inside) = Stack of thylacoids (semi-liquid)
ENERGY-CONVERTING ORGANELLES Chloroplasts are double-membrane-bounded. thought to have evolved from the two-layer membrane of cyanobacteria blue-green algae (prokaryote) Which took up residence (endsymbiosis) Chloroplasts have about 100 of their own genes (DNA), and ribosomes the genomes being quite similar to sections of cyanobacteria genomes Mitochondriaharvest chemical energy from food Mitochondria carry out cellular respiration, the conversion of glucose to ATP. found in all cells of eukaryotes, except a few anaerobic protozoans. are double-membrane-bounded organelles with two membrane spaces, the intermembrane space and the mitochondrial matrix. the ATP -generating electron transport system is embedded in the inner membrane (cristae), and chemical reactions occur in compartments between membranes. Contain DNA, RNA and ribosomes 37 genes in humans Mitochondrion Outer membrane mtdna is only inherited from mother (maternal DNA) Origin of mitochondria Bacteria invaded primitive cells that only carried out Respiration Part I - Glycolysis Intermembrane space Inner membrane Cristae Matrix TEM 44,880?
THE CYTOSKELETON AND RELATED STRUCTURES Microfilaments of actin Enable cells to change shape and move Microtubules give the cell rigidity And provide anchors for organelles and act as tracks for organelle movement Actinsubunit Microfilament 7 nm Fibrous subunits 10 nm Intermediate filament Tubulinsubunit Microtubule 25 nm Polar or water soluble end of phospholipid Fatty acid tails Small non-polar lipids and small molecules CO 2, O 2 can pass thru membrane, Including H 2 O since it is small (despite that it is polar) Sugars, amino acids, nucleic acids polar Aquaporins also pass water
Cell Biology I.Overview II. Membranes How Things Get in and Out of Cells A. Membrane Structure B. Membrane Function 1. semi-permeable barrier 2. transport Net diffusion Net diffusion equilibrium Cell Biology I.Overview II. Membranes How Things Get in and Out of Cells A. Membrane Structure B. Membrane Function 1. semi-permeable barrier 2. transport - diffusion Net diffusion Net diffusion Equilibrium Net diffusion Net diffusion equilibrium Net diffusion Net diffusion Equilibrium
Cell Biology I.Overview II. Membranes How Things Get in and Out of Cells A. Membrane Structure B. Membrane Function 1. semi-permeable barrier 2. transport - osmosis Other Means to get materials across membrane