Plant and animal cells Label the bits you
Plant and animal cells Label the bits you recognise
Similarities Plant cell Animal cell
Differences Plant cell Animal cell
Plant Cells (animal cells + a bit)
Chloroplasts occur in a variety of shapes and sizes, such as corkscrewlike ribbons or bracelet-shapes found in certain green algae. The chloroplasts of higher plants, however, tend to be shaped somewhat like two frisbees glued together along their edges, and when they are sliced in median section they resemble the outline of a football. Chloroplasts may be from 2 to 10 micrometers in diameter, and each is bounded by an envelope consisting of two delicate unit membranes. The outer membrane apparently is derived from endoplasmic reticulum whereas the inner membrane is believed to have orginated from the cell membrane of a blue-green bacterium. Within is a colorless, fluid, enzyme-containing matrix, called the stroma. Grana (singular: granum), which are stacks of coin-shaped double membranes called thylakoids are suspended in the stroma. The membranes of the thylakoids contain green chlorophyll and other pigments. Theses "coin -stacks" of grana, are vital to life as we know it on our planet today, for it is within the thylakoids that the first steps of the all-important process of photosynthesis occurs.
5 Minute Poster The structure and function of POLYSACCHARIDES
POLYSACCHARIDES Polysaccharides are large polymers of the monosaccharides Unlike monosaccharides and disaccharides, polysaccharides are either insoluble or form colloidal suspensions The principal storage polysaccharides are STARCH AND GLYCOGEN Starch is a polymer of alpha glucose and is, in fact, a mixture of two different polysaccharides – AMYLOSE AND AMYLOPECTIN AMYLOSE – long unbranched chain of glucose units STARCH AMYLOPECTIN – highly branched polymer of glucose units
AMYLOSE STRUCTURE Amylose is formed by a series of condensation reactions that bond alpha glucose molecules together into a long chain forming many glycosidic bonds The amylose chain, once formed, coils into a helix
AMYLOSE STRUCTURE THE AMYLOSE HELIX
AMYLOPECTIN STRUCTURE Amylopectin consists of a straight chain of alpha glucose units with branch points occurring at approximately every twelth glucose unit along the straight chain The branch points form when carbon 6 of a glucose molecule in the straight chain forms a glycosidic bond with carbon 1 of a glucose molecule positioned above the chain
AMYLOPECTIN STRUCTURE This highly branched amylopectin molecule is wrapped around the amylose to make up the final starch molecule This large insoluble molecule with branch points that allow for easy access for enzymes when breaking down the molecule, makes starch an ideal food storage compound
GLYCOGEN Glycogen is often referred to as animal starch Glycogen has the same overall structure as amylopectin but there is significantly more branching in this molecule More of these branch points form
STRUCTURAL POYSACCHARIDES Cellulose is one of the most important structural polysaccharides as it is the major component of plant cell walls Cellulose is a polymer of beta glucose units where each glucose molecule is inverted with respect to its neighbour 6 CH 2 OH H 4 HO 5 H OH 3 H O 1 OH GLUCOSE H OH H 5 2 CH 2 OH 2 3 4 6 OH H O 6 CH 2 OH GLUCOSE 1 5 1 O 4 H OH 3 H OH H O 1 3 4 OH H 5 2 OH GLUCOSE 2 H 1 O 6 CH 2 OH GLUCOSE 4 glycosidic bonds The orientation of the beta glucose units places many hydroxyl (OH) groups on each side of the molecule Many parallel chains of beta glucose units form and each chain forms hydrogen bonds between the OH groups of adjacent chains
STRUCTURAL POYSACCHARIDES The bundles of parallel chains forming hydrogen bonds with each other creates a molecule that confers rigidity and strength to the structures of which they form a part hydrogen bonds between parallel chains of beta glucose The rigidity and strength of plant cell walls is a consequence of the incorporation of cellulose into their structure
What am I?
Structure of cellulose • Like starch, cellulose is composed of a long chain of at least 500 glucose molecules. Cellulose is thus a polysaccharide. Several of these polysaccharide chains are arranged in parallel arrays to form cellulose microfibrils. • The individual polysaccharide chains are bound together in the microfibrils by hydrogen bonds. The microfibrils, in turn, are bundled together to form macrofibrils. • The microfibrils of cellulose are extremely tough and inflexible due to the presence of hydrogen bonds.
C. O. W!! What is the most “challenging” concept we have discussed today?
What is the middle lamella? What is the apoplast transport system? What is the symplast transport system? What are plasmodesmata?
Write the question!! 1. 2. 3. 4. 5. 6. Beta glucose Cellulose Middle lamella Apoplast Symplast Plasmadesmata
Function of the Cellulose cell wall
Chloroplast ultrastructure 1. outer membrane 2. intermembrane space 3. inner membrane (1+2+3: envelope) 4. stroma (aqueous fluid) 5. thylakoid lumen (inside of thylakoid) 6. thylakoid membrane 7. granum (stack of thylakoids) 8. thylakoid (lamella) 9. starch 10. ribosome 11. plastidial DNA 12. plastoglobule (drop of lipids)
Function of a chloroplast
• • • Haemogloblin Protein structures Oxygen dissociation Glucose Cellulose Glycogen Cells Cell wall Chloroplasts • • Blood circulation Capillaries Veins Kidneys Liver Arteries Tissue fluid Lymph