Cells, Organelle, Osmosis, Photosynthesis

1. Eubacteria: bacteria
2. Archaebacteria: extreme bacteria
3. Protista: seaweed and singlecelled critters, can be plant or animal-like
4. Animalia: animals, no cellwalls, heterotrophs (must eat)
5. Fungi: fungus, cell walls and heterotrophs
6. Plantae: plants

Plants: multicellular organisms that are sessile , produce their own food from inorganic matter by the process of photosynthesis and have rigid cell walls
– Multicellular: contains more than one cell
– Sessile: doesn’t move under its own power
– Inorganic matter: not alive, CO
2
, H
2
O
– Photosynthesis: Produces glucose sugar from sunlight, CO
2
– Cell Walls: surround the cell and give it shape and H
2
O

1. Algae (live in water, single celled, and has no roots = Protist)
2. Seaweed (lives in water, no roots = Protist)
3. Fungi (consumes dead organisms, no photosynthesis)
4. Bacteria (unicellular)
5. Animals (no photosynthesis, can move)
• Some plants live in water or don’t photosynthesize (parasites). They are considered plants because they are descended from legitimate photosynthesizing, land-dwelling plants

• Organelle: parts of a cell
• All living things are made of cells that are surrounded by a cell membrane, which keeps the inside separated from the outside and allows certain molecules through.
• Plants and animals are both eukaryotes (DNA is enclosed in a nucleus)
• The cytoplasm is everything between the cell membrane and the nucleus. It holds the organelle and does chemical changes needed to keep the cell alive.
• Both have mitochondria that produce ATP energy for the cell.

• Plant cells are different from animal cells in several ways:
• Rigid cell wall that is OUTSIDE the cell membrane. It is the box that contains the cell.
• Central vacuole that stores water
• Chloroplasts that perform photosynthesis
- Chloroplasts were originally freeliving photosynthetic bacteria that got swallowed by a primitive eukaryotic cell and developed a beneficial symbiotic relationship inside the cell
(endosymbiont theory)

Cell Walls:
• The cell wall is mostly made of cellulose.
• Cellulose is a molecule made of many glucose sugar molecules linked in long chains
• Starch is also made of many glucose units, but the connection between the glucoses is different.
• Almost all organisms can easily digest starch, but only bacteria and protists can digest cellulose.
Glucose
Sugar

• All cells have to deal with osmosis:
• Water moves from areas of high water concentration (lots of water molecules and less salt) to areas of low water concentration
(more salt and less water).

• Hypertonic:
High water concentration inside the cell
• Isotonic: equal inside and out
• Hypotonic:
High water concentration outside the cell
Water leaves, cell shrinks Water leaves and enters, cell stays the same
Water enters, cell expands

• There is usually a higher concentration of salt particles inside the cell
• So water moves into the cell, which would cause the cell to swell and burst.
• The cell wall acts as a box to prevent the cell from bursting.

• If the plant isn’t getting enough water (or if the plant is put in a high salt solution), the water supply in the central vacuole moves into the cytoplasm.
• This causes the cell to shrink away from the cell wall.
• The plant wilts

• The plant takes in:
1. Light energy from the sun
2. Carbon dioxide (CO
2
) from the air
3. Water (H
2
O) from the soil
• The plant produces:
1. Oxygen gas (O
2
)
2. Sugar (C
6
H
12
O
6
)
• Photosynthesis happens in the chloroplasts.