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Cells. Regions of cells Middle lamella = pectin Bacteria/fungi break down causing fruit/vegetable rot Like “mortar” between two bricks! Primary cell wall = cellulose and pectin Secondary cell wall = cellulose and lignin (not always present). Pectin. Rot in fruit. Cells.
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Cells • Regions of cells • Middle lamella = pectin • Bacteria/fungi break down causing fruit/vegetable rot • Like “mortar” between two bricks! • Primary cell wall = cellulose and pectin • Secondary cell wall = cellulose and lignin (not always present)
Cells • Cell walls are NOT solid! • Pierced by plasmodesmata (pores and strands that connect cells) • Plasmamembrane = semipermeable
Cells • Cytoplasm • 85-90% water • 10-15% organic(carbon-based) and inorganic substances • Dissolved (salts and carbohydrates = CHO’s) • Colloidal (proteins and fats)
Cells • Similar to Jell-O® • First made in 1897 • Every four seconds, a box of JELL-O gelatin is sold in the United States! • From the Chicago Tribune of March 5th, 1997 • Jell-O = "hide trimmings," animal tissue that is rendered, purified, filtered, and then purified again, leaving a protein called collagen • “The gelatin that is the building block of Jell-O is so purified that the FDA doesn't regard it as a meat product. Likewise, all but the strictest vegetarians find Jell-O acceptable”
Cells • Nucleus • Contains chromosomes • DNA = deoxyribonucleic acid • mRNA • Relays genetic info. from nucleus to ribosomes (often attached to the ER, where proteins, such as enzymes, are made)
Cells • Plastids (in the cytoplasm) • Leucoplasts (colorless) contain starch • Chromoplasts (colored) • Chloroplast = chromoplast that contains chlorophyll (20 - 100 chloroplasts per cell in a green leaf!) • Where photosynthesis occurs • Grana = stacked like coins, contains chlorophyll, receive light • Stroma = surrounds grana where CO2 is converted to CHO’s
Cells • Mitochondria = power center for cell • Proteins and phospholipids • ATP (adenosine triphosphate) carries energy • Vacuoles = membrane-lined cavities in the cytoplasm filled with cell sap (water, salts, organic materials) • Helps control plant turgor
Cell sap 90% water 8% sugars 2% minerals/AA/other
Mitosis • Cell division • End up with the same # of chromosome as your started with! • Can lead to plant growth
Cell enlargement • What causes plant growth!! • In a region just behind the area of cell division (meristem)
Types of cells • Parenchyma cells • Juicy edible parts of fruits and veggies • Thin walled • Contain lots of water
Types of cells • Collenchyma cells • Thick-walled cells • Coarse and “gritty”
Types of cells • Sclerenchyma cells • Fibrous • For support
Types of cells • Importance of middle lamellae in cooking • ‘Russet Burbank’ potatoes • Ideal for baking, mashing & processing • Middle lamellae breaks down easily • Cells remain intact • Mealy texture • ‘Red Pontiac’ potatoes • Ideal for boiling and frying • Middle lamellae does not break down
Middle lamellae stays intact
Roots • Why? • Anchor plant • Absorb mineral nutrients • Absorb water • Store nutrients (CHO’s) and water
Roots • Parts: • Root cap • Meristem • Zone of elongation • Maturation zone