Cells, Tissues, And organ systems

1. TODO Science test

2. Topics:

The cell
Animal systems
Plant systems

3. CELL THEORY

All livikng things are composed of cells
All cells come from pre-existing cells
The cell is the basic unit of life.

The cell theory has helped scientists to understand the workings of the human body and the bodies of other living things.

3.1. Plant and Animal Cells

3.1.1. Unicellular vs Multicellular lviing things

Unicellular:
- Composed of only one cell
- Bacteria protists, and some fungi.
Multicellular
- Composed of many specialized cells
- Plants, animals, and some fungi

3.1.2. Animal cell structures and plant cell structures

Structure	Function	Plant	Animal	Requires electron microscope
Nucleus	Controls the activites of the cell and houses the chromosones	[X]	[X]	[ ]
Chromosones	Strands of DNA found inside the nucleus, they contain the genetic material	[X]	[X]	[ ]
Cell membrane	Controls material I/O(nutrients and waste). Also known as the gate-keeper of the cell	[X]	[X]	[ ]
Cytoplasm	Watery fluid, allows materials to be transported in the cell, stores materials	[X]	[X]	[ ]
Vacuole	Filled with fluid, stores water and nutrients.	[X]	[X]	[ ]
	. such as sugar and minerals(or in some cases food)
Contractile Vacuole	Expands and contracts to collect and expell water.		[X](Protists)	[ ]
Flaggellum	Little whip that propels cells.(Example: sperm)	[X]		[ ]
Cilia	Tiny hairs that move external substances. Means eyelash.	[X]		[ ]
	Example: paramecium
Mitochondria	Provides energy for the cell. "The mitochondria is the powerhouse of the cell!" Cellular	[X]	[X]	[X]
	respiration occurs here, mitochondria release energy by combining glucose with oxygen to form
	carbon & water.
	Cellular respiration allows living things to release energy from food.
	CH₂O+O₂→ CO₂+H₂O+energy
Ribosomes	protein molecules are manufactured here using information from the nucleus and molecules	[X]	[X]	[X]
	From the cytoplasm. Proteins are large molecules that are needed for cell growth, repair, and
	reproduction.
ER	Folded membranes that carry materials through the cytoplasm. Sometimes ribosomes are
	attached to the ER and it is called the "Rough" ER. Otherwise it is the "Smooth" ER	[X]	[X]	[X]
Golgi Apparatus	Used for protein storage. Puts proteins into packages called vescicles that carry the proteins	[X]	[X]	[X]
	to the surface of the cell where they are released to the outside.
Lysosomes	Contain special proteins that break down large molecules into smaller ones.	[X]	[X]	[X]
	The smaller ones can be reused to build larger molecules. They also kill & digest invading
	organisms
Chloroplast	Where photosynthesis occurs	[X]	[ ]	[ ]

4. Cell membranes

Allow some materials to enter or leave depending upon the size of the molecule, this is called a selectively permeable membrane.
Permeable means permitting passage and Impermeable means not permitting passage
See example of cell membrane below: ex: membrane allows x particle in but doesnt allow dust particle stuff.

4.1. Diffusion

The movement of molecules from an area of higher concentration to low concentration

4.1.1. Diffusion and cells

Movement of molecules through the cell membrane can occur through diffusion.
CO₂ molecules, tend to become more concentrated inside the cell than outside, so they will diffuse out of the cell.

4.1.2. Osmosis

Osmosis is a type of diffusion in which water moves across a selectively permeable membrane.

Facts:
- Water molecules are small and pass through a cell membrane easily.
- Water molecules are constantly passing through the cell membrane both in and out of the cell.
- If an imbalance occurs, more water molecules will move in the direction of the low concentration of water.
  - Example: Swelling of resins and other seeds when they are soaked in water.
Turgor pressure

If the concentration of water outside a plant cell is higher than inside it, water molecules enter the cell by osmosis. The water fills the vacuoles and cytoplasm, causing them to swell up and push against the cell wall. This outward pressure is called turgor pressure. and causes crispness some beans have distinct leaf positions during the day and night.

4.2. Parts of the microscope labeling diagram thing

Objective lens The 3 lens

4.3. Cells and Cell systems

cells remember these Epithilelial tissue: linings & skin Connective tissue: connects stuff Nervous tissue: nerves and stuff muscle tissue: muscle tissue

4.4. Amoeba and Paramecium

4.4.1. Amoeba

Blob-like organisms that move by stretching out a branch of cytoplasm called a “pseudopod” (false foot). The pseudopod anchors to an object and the rest of the cell is dragged toward it. The crawling motion is also used for feeding, as it wraps itself around the food.

4.4.2. Paramecia

Oval-shaped organisms that use hair-like structures called cilia to create water currents that move them around. Cilia around the paramecium’s oral groove (primitive mouth) draw food into the groove. Bacteria and other smaller cells are their main food source.

4.5. Diatoms & Euglena

4.5.1. Diatoms

Found in fresh and saltwater Contain chlorophyll and can make their own food Encased in two thin shells joined together

4.5.2. Euglena

Have an eyespot to see light. Like a plant and an animal cell. Autotroph when theres lots of light and Heterotroph when there is a lack of light Has a contractile vacuole that expels excess water.

4.6. Cell Wars

4.6.1. A disease is a condition that interferes with the well-being of an organism.

Many diseases are caused by agents that invade the body and interfere with the normal activities of the cell. The invasion is called infection.

Bacteria, fungi, and parasitic worms rob cells of their nutrients or produce waste products that poison cells.

Viruses are not living things because they are not true cells. A virus contains no nucleus, cytoplasm, organelles, or cell membrane. The virus is a small strand of genetic information covered by a protein coat. They are only active when invading a living cell. They take over the cell and turn it into a factory for making more viruses. Viruses can cause cold sores, colds, and the flu.

4.6.2. The defenders

Your immune system defends you by destroying invaders. White blood cells engulf and digest invading bacteria. The white blood cell’s lysosomes release special chemicals that destroy the invaders but also destroy the white blood cell.

Antibodies – made by a special type of white blood cell. They are large molecules that lock onto invading organisms.