College Bio all chapter 4

Lysosomes:

Break things down (pathogens, waste, etc.)

Microfilaments (cytoskeleton):

• Narrow

• Focused on movement (actin-myosin)

Intermediate Filaments (cytoskeleton):

Structure

Microtubules (cytoskeleton):

• Wide

• Tracks for internal or external movement

Flagella (make up/microtubules):

• Few

• Large movement

Cilia (make up/microtubules):

• Many

• Small movement

Extracellular Matrix (cellular connection):

• Like cytoskeleton, but outside

• Usually involves proteins (collagen < “glue”)

Plasmodesmata (cellular connections):

• Allows connection between plant cells

• Cell wall bypassed

Desosomes (cellular connections):

• Strong connection between animal cells

• “Sheet like”, so useful in heart, skin, “stretchy” areas

Gap Junctions (cellular connections):

• Like “plasmodesmata” but for animal cells

• Nerve cells and neurotransmitters

Centrosome:

Only found in animals

Lysosomes:

Usually only in animals

Cell Wall:

Only in plants

Chloroplasts:

Only in plants

Central Vacuole:

Only in plants

Rough (endoplasmic reticulum):

Ribosome

Smooth (endoplasmic reticulum):

Synthesis of carbs/lipids

Golgi Apparatus:

• “Amazon Fulfillment Center”

• Sorts, packages, and distributes lipids/proteins

Why they’re small:

• Surface area allows nutrients in, waste out

• Volume requires more nutrients, etc.

• Volume increases faster than surface area

For a cube:

• SA = L x W x 6

• V = L x W x H’

• SA:V ratio - 6:H

For other small shapes, same pattern:

• SA squares

• V cubes

Components of Eukaryotic Cells

• Membrane bound organelles

- nucleus, endoplasmic reticulum, mitochondria, etc.

• “Rod-shaped” chromosomes

4 Shared Components (prokaryotes):

• Plasma membrane

• Cytoplasm

• DNA

• Ribosomes

- no membrane - bound organelles / does have “nucleoid”

Cell Wall (components of prokaryotes):

Rigid

Cell Capsule (components of prokaryotes);

Gelatinous

Flagella (hair-like structure):

Locomotion

Pili (hair-like structure):

Exchange genetic material

Fimbriae (hair-like structure):

Attach to host cell

Microscopes:

Left is right, up is down

Light Microscopes:

• Cells are “transparent”, so staining required

- can kill cells

• Ocular magnification x objective magnification

Electron Microscopes:

• Can’t view living cells (vacuum needed)

Pillars of Cell Theory:

• The cell is the basic unit of life

• All living things are made up of cells

• All cells come from pre-existing cells

Contributors:

• Hooke

• Leeuwenhoek

• Schwann

• Virchow