2 main types Prokaryotic Cells Primitive no membrane

2 main types • Prokaryotic Cells – Primitive, no membrane bound organelles (nucleus, chloroplast etc), – Bacteria • Eukaryotic Cells – More advanced cells – Animals, plants, fungi etc

• Cell membrane - Double lipid layer with embedded proteins - Living - In plants & animals - Selectively permeable (allows some things in, but not all)

• Nucleus - Membrane bound - Largest organelle - Contains chromosomes (heredity material) - Control center for the cell - Surrounded by nuclear envelope which contains pores

• nucleolus - Inside nucleus - Contains and makes RNA - (ribonucleic acid)

• Cytoplasm - Gel like substance - Most cellular activity occurs here - Some Cytoplasm ‘streams’

Frankenstein pumpkin

Cytoplasmic streaming in elodea

• Mighty mitochondria - Double membrane - Inner membrane is folded which increases surface area - Contains DNA - Releases energy through aerobic respiration -

• Endoplasmic Reticulum (ER) - Fluid filled, membrane bound channels Transports materials Smooth ER- no ribosomes Rough ER- contains ribosomes

• Ribosomes - Small ‘dots’ attached to ER or free-floating - Produce proteins

• Golgi body - Stacks of flattened membranes - Packaging, storage, transports proteins - Produces lysosomes

• Lysosome - Sacks of digestive enzymes - Usually in animal cells only

• Centriole - Active during cell reproduction - In animal cells only

• Cell wall - Nonliving - Cellulose - In Plant cells only

• Chloroplast - Green Contains chlorophyll Where photosynthesis occurs In Plant cells only

• Large central vacuole - Filled with fluid which provides turgor or hydrostatic pressure for the cell (makes it firm) - storage - In Plant cells only (Animal cells have small vacuoles)

Lab: How plant & animal cells differ • Cheek cell • Elodea cell

Plant cells Animal cells Both plant & animal cells Put the following organelles where they belong: Cell membrane, centriole, cell wall, cytoplasm, nucleus, chloroplast, nucleolus, lysosome, ER, mitochondria, ribosome, golgi body, central vacuole

Lab: observing cork & onion cells • Cork cell harvesting • Onion cells

• Cell membrane - Double lipid layer with embedded proteins - Living - In plants & animals - Selectively permeable (allows some things in, but not all)

Diffusion – Movement of a substance from high concentration to low concentration until dynamic equilibrium is reached – Once dynamic equilibrium is reached diffusion occurs equally in both directions Osmosis – The diffusion of water Facilitated Diffusion – Proteins in cell membrane aid diffusion

Solutions can be: 1. Isotonic solution The concentration of solutes (salt or sugar) is the same inside & outside the cell Cells remain the same size

2. Hypotonic solution The solution contains a lower concentration of dissolved substances (more watery) than the cells in it Cells enlarge & animal cell may explode High Turgor Pressure

3. Hypertonic solution The solution contains a higher concentration of dissolved substances (less watery) than the cells in it Cells shrink Become more flaccid/plasmolyzed

Passive Transport – Doesn’t require energy – Molecules move down a concentration gradient (from high to low concentration) – Ex: diffusion, osmosis Active Transport – Requires energy from ATP – Molecules move up a concentration gradient (from low to high concentration)

Active transport – occurs 3 ways

Through a transport protein

Cell ingests food

Cell drinks liquid

Lab: diffusion through a membrane

Benedicts Solution: • Turns from blue to orange/red in the presence of simple sugars when heated

Iodine: • Turns from rusty red to blue/black in the presence of starch (complex carbohydrate)

• • • bread potato sugar flour Old Bay spice cornstarch egg shell carrot rice cooked spaghetti green bean liquid sizing from our laundry area- works like starch without the stiffness