2b - LESSON Cytology (PRINT).notebook

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September 23, 2016

DPSS Biology 12

Mrs. Frost

2b - LESSON Cytology (PRINT).notebook

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September 23, 2016

EukaryoteProkaryote

The Cellular Level of Organization

Cell Theory- one or more cells- basic living unit of structure and

function- all cells come from other cells

Cell (basic unit of life)

- "before a nucleus" (nucleoid & plasmid)- no membrane bound organelles- cell wall, capsule, pili- e.g. bacteria & archae

- "true nucleus"- has membrane bound organelles- e.g. animals & plants

2b - LESSON Cytology (PRINT).notebook

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September 23, 2016

Cell Size

Scale of the universe: htwins.net/scale2/

Cells must remain SMALL to keep an ideal ratio of surface area and volume (as volume increases, proportionate surface area decreases).

Adequate surface area is vital as it allows substances, such as glucose and oxygen, to diffuse in and wastes, such as carbon dioxide, to diffuse out.

Sooooo... why are some cells, like a chicken egg, so big?Because it is not actively metabolizing, just dividing without growth.

Fig 3.2 (pg.67)

2b - LESSON Cytology (PRINT).notebook

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Cell Structures

Plasma membrane- Phospholipid bilayer- Separates cell from surroundings, regulates passage in and out of cell

Mitochondria- "Power house"- Performs cellular respiration to create ATP

Vesicles- Tiny membranous sacs which store substances

Cytoplasm- Semifluid medium - Composed of water, salts, and dissolved organic molecules

Nucleus Control center of the cell, stores genetic info, synthesis of DNA & RNA

2b - LESSON Cytology (PRINT).notebook

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September 23, 2016

Cell Structures

Smooth ER- Synthesis of phospholipids- Specialized functions (testosterone in testes, detoxifying in liver)

Golgi Apparatus- Modifies lipids and proteins from the ER, sorts them and packages them into secretory vesicles- Also produces lysosomes.

Ribosomes- Protein synthesis, made of two subunits

Rough Endoplasmic Reticulum (ER)- Folding, modification & transport of proteins

Lysosome Contain hydrolytic digestive enzymes to breakdown materials within the cell

Centriole 9+0 patternMicrotubule organizing center for the cell (assembly & disassembly)

2b - LESSON Cytology (PRINT).notebook

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Cell Structures ChloroplastSite of photosynthesis: turns energy from sun into carbohydrates

Cell Wall- Contains cellulose- Provides support & protection

Vacuole - Large one in plants cells for support- Numerous smaller ones in animal cells

Cytoskeleton- Keeps cell shape- Allows movement of cell and its organelles- assembles and disassembles as needed

2b - LESSON Cytology (PRINT).notebook

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Cytoskeleton Specifics

Actin Filament- Form a dense web under cell membrane- Interact with myosin (motor molecule)

Intermediate Filaments- Fibrous and ropelike- Perform a structural role

Microtubules- Hollow cylinders- Radiate from centrosome- Maintains cell shape & act as tracks for organelles- Interact with kinesin & dynein

2b - LESSON Cytology (PRINT).notebook

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September 23, 2016

Cilia & Flagella

9 + 2 arrangement