CELLULAR COMPONENTS
& PROCESES

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The cell is the unit of structure and function in living things.
All cells arise from preexisting cells.
The cells of all living things carry on similar chemical activities.
All cells carry on their metabolic activities in organelles.

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Prokaryoticcells that DO NOT have a nucleus or other cell ORGANELLES
Eukaryoticcells with a NUCLEUS & cell ORGANELLES
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Which is more complicated?
REMEMBER YOU ARE EUKARYOTIC!

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The parts of a cell that carry out a function are called cell ORGANELLES :
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All cells have the following organelles:
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Cell Membrane
Cytoplasm
Ribosomes
Cytoskeleton

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Nucleus
Nucleolus
Mitochondria
Golgi Body Complex
Endoplasmic Reticulum
Vacuole
Lysosome
Centrioles (ANIMAL ONLY)
Only Plant Cells have all of the above &:
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Cell Wall
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Chloroplast

 little “organs” of the cell
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Organelles are present in BOTH plants and animals
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Carry out cellular functions!

 cellular control center
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Controls cellular activity contains hereditary material
(DNA in chromosomes)
 self duplicating structure divides when the cell divides

 surrounds nucleus allowing certain materials to enter and leave

 round organelle in the nucleus
 usually a pair
 involved with the synthesis of
RNA in the ribosomes

 sites of protein synthesis in the cytoplasm
 may be free in the cytoplasm or attached to the endoplasmic reticulum

 cytoplasmic channels from the cell membrane to the nuclear membrane
 associated with the storage, synthesis, and transport of materials within the cell
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“HIGHWAY” for cell transport

 fluid like material between the cell membrane and the nucleus
 over 80 % water
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“HOLDS” cell organelles in place
 site of most organelles and cellular chemical reactions

 membrane bound cytoplasmic spaces containing materials
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** Vacuoles are crucial in singlecelled organisms
Two Types:
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Food vacuole--store and digest ingested food
Contractile vacuole-pumps excess water from cells maintaining homeostasis

 pouch containing digestive enzymes
 digest bacteria and some foods entering the cell
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Breaks down complex molecules into simpler molecules (SLICE)
 breakdown worn out cell organelles

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"Powerhouse of the cell"
 carries on cellular respiration
(contains respiratory enzymes that make ATP) ( energy molecule )
 may contain DNA--is self duplicating-- divides when the cell divides
 found in greater #s in active cells

 usually located near the nucleus
 synthesizes, packages, and secretes cellular products
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Packages waste & harmful materials

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The cell membrane is SEMI-PERMEABLE selectively regulates the flow of materials to and from the cell--thus maintaining chemical homeostasis within the cell
The membrane acts like a BOUNCER only allowing certain things in and out of the cell It is made up of a lipid bilayer double layer of FAT "Fat sandwich" transport through the plasma membrane likely occurs through these globular proteins (Fluid mosaic model)

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Hydrophilicattracts water
Hydrophobicrepels water
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Why is it important that the cell membrane is made up of small phospholipids?

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Centriolea cylindrical structure found in the cytoplasm which appears to function during the division of certain animal cells
(usually near the nucleus)
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Helps animal cells divide

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Cell Walla nonliving structure which surrounds and supports the cell - composed mostly of cellulose
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Gives the plant cell structure & support
Chloroplasts - green in color-double membrane - contain the green pigment chlorophyll which carries on photosynthesis
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Uses the sun’s energy to make food for the plant

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 the conversion of light energy to chemical energy by chlorophyll in chloroplasts
Overall Net equation for photosynthesis:
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6 Water + 6 Carbon dioxide yields glucose + 6 oxygen (when catalyzed by chlorophyll in the presence of sunlight)

 cell - unit of structure of all life
 tissue - composed of groups of similar cells
 organs - composed of groups of tissues functioning together
 organ systems - composed of groups of organs functioning together

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Passive transport - movement of substances through a membrane from a region of high to a region of low concentration - no energy needed (ATP) - diffusion and osmosis are examples of this
Active transport - movement of substances through a membrane from a region of low concentration to a region of high concentration requires cellular energy (ATP)

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Whether passive or active transport is needed depends on the
CONCENTRATION GRADIENT
The concentration gradient is the difference in the concentration of a substance in two different spaces
Concentration - the amount of a particular substance in a contained area compared with the amount of the same substance in another area
Translation: Amount of something in a space (water, salt, sugar, iron,)

PROCESSES OF THE PLASMA
MEMBRANE
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There are two types of passive
transport: Diffusion and
Osmosis
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The goal of both diffusion and osmosis is to reach
EQUILIBRIUM within the cell
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Equilibrium is a condition in which the movement in one direction is equal to the movement in another direction

 the tendency of molecules to move from an area of higher concentration to an area of lower concentration
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(concentration gradient- diff in conc. between 2 regions)

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 movement of water through a membrane from a region of higher to lower con.
Solute - substance being dissolved in a liquid (ex. salt)
Solvent - substance doing the dissolving
(ex. water)
Permeability - the extent to which a membrane will allow particular sized molecules to pass
Semi-permeable membrane (selectively permeable)-allows some molecules to pass but not others

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So, describe how “Kool-Aid”® is made with regard to the terms
“solute” and “solvent”. What is the
“universal solvent”?

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When comparing two solutions there are three possible relationships, We Identify the relationships by determining what would happen if a cell were placed in the solution.
HypertonicA solution that causes a cell to shrink because of osmosis.
Meaning water leaves the cell.
HypotonicA solution that causes a cell to swell because of osmosis meaning water rushes into the cell.
Isotonic -A solution that causes no change in cell size. Meaning there is no movement of water.

If the fluid outside the cell has…
…less water than is present inside the cell
Then the outside fluid is…
Water moves… Effect on the cell?
…more water than is present inside the cell
…same amount of water as inside the cell

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So, answer this question…. Why do
“establishments” offer free popcorn, peanuts, and pretzels to their patrons if they are serving beverages? What changes are taking place in the body to initiate the need for more beverages?

 the movement of a substance against the concentration gradient. (uphill)
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Active transport requires cell to
USE ENERGY

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Sodium pump - transports three sodium ions out of the cell and two potassium ions into the cell
Both are against the concentration gradient
The energy needed to perform this activity is supplied by ATP
(adenosine tri-phosphate)
ATP is a unit of energy made by the cell

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Endocytosisthe movement of a substance into the cell by a vesicle. A vesicle is a form of packaging that is used by cells.
Exocytosisthe movement of a substance out of the cell by a vesicle.
Phagocytosiscytoplasm of cell surrounds and engulfs particle--ex. ameba and white blood cell
Pinocytosisplasma membrane
"pinches in" to permit entry of molecules too large to diffuse through