Biology Chapter 6 A Tour Of The Cell

Front 1

Cell Theory

Back 1

- The unifying concept in biology that says all organisms are composed of cells

- All cells come only from preexisting cells because cells are self-reproducing

- Cells are the basic units of structure and function in organisms

Front 2

Matthais Schleiden

Theodor Schwann

Rudoph Virchow

Back 2

- Scientists (2) whose work aided in the origination of the cell theory

- Scientist who said cells come only from preexisting cells

Front 3

1mm - 1um (micrometer)

Back 3

Cell Diameter Range

- Usually too small to see with naked eye

- Light microscope utilized

Front 4

Contrast

Back 4

- Allows differentiation between cell structures

- Usually a stain

Front 5

Surface-Area-to Volume Ratio

- Need large surface area of plasma membrane to adequately exchange materials

Back 5

Why are cells so small?

Front 6

Compound Light Microscope

Back 6

- Light is passed through specimen then it is focused by a series of glass lenses

- Maximum magnification is about 1000X

- Resolves objects up to 0.2um, 500X better than human eye

Front 7

Bacteria

Back 7

- Can cause diseases but are also environmentally important as decomposers

- Can be useful in manufacturing products and drugs

Front 8

Prokaryote size

Back 8

- Range is about 1-1.5um wide and 2-6 um long

Front 9

Coccus

Bacillus

Spirillum

Spirochete

Back 9

Shapes of Prokaryotes

- Spherical

- Rod-shaped

- Rigid Spiral

- Flexible Spiral

Front 10

Plasma Membrane (Proteins in Phospholipid bilayer)

Cell Wall (Peptidoglycan maintains shape of cell and strengthens)

Glycocalyx (Rigid layer)

Back 10

3 Components of the Cell Envelope (Prokaryotes)

Front 11

Cytoplasm

Back 11

- Semifluid solution encased by plasma membrane

- Contains water, inorganic/organic molecules and enzymes

Front 12

- Perform specific functions

- Isolate reactions from other reactions

Back 12

Eukaryotes are compartmentalized by organelles for these 2 reasons:

Front 13

Endomembrane System: Organelles that communicate with one another via membrane channels or small vesicles

Energy-related: Independent and self-sufficient

Back 13

2 Classifications of Organelles and how they work-

Front 14

Organelles

Back 14

- Production of specific molecules take place in or on _______________ by enzymes in membranes

Front 15

Vesicles

Back 15

- Products are transported around cell by sacs made of membrane material called:

Front 16

Cytoskeleton

Back 16

- Vesicle move around using these protein fibers like railroad tracks, which helps maintain cell shape, assists in movement of cell and organelles, makes internal transport possible

- May be compared to bones and muscles of animal because dynamic and responds to environmental changes

- Can assemble and disassemble as needed

Front 17

Cell walls

Back 17

Plant cells, fungi and many protists have _____________ for a structural function, eg. cellulose in plants

Front 18

Nucleus

Back 18

- Believed to have evolved by the folding in of a portion of the plasma membrane

Front 19

Chromatin

Back 19

- Contained in nucleus

- Consists of DNA and proteins

Front 20

Endosymbiotic Theory

Back 20

- Hypothesis that energy organelles such as the mitochondria and chloroplasts may have originated when eukaryotic cells engulfed smaller prokaryotic cells

- Since they have their own DNA and can replicate independently

Front 21

Microtubules

Intermediate filaments

Actin filaments

Back 21

3 Types of filaments of the Cytoskeleton

Front 22

Microtubules

Back 22

- Hollow protein cylinders that move organelles

- Made of two globular proteins called a and b tubulin

- Pairings of a and b tubulin form structures called dimers, which then arrange themselves into tubular spirals of 13 dimers around

- Interacts with 'motor' molecules such as kinesin and dynein to cause movement of organelles

Front 23

Intermediate Filaments

Back 23

- Protein fibers that provide stability of shape

- Rope like assembly of fibrous polypeptides

- Supports nuclear envelope

- Cell-cell junctions

Front 24

Actin filaments (Aka Microfilaments)

Back 24

- Protein fibers that play a role in cell division and maintains cell shape

- Extremely thin, like twisted pearl necklace

- Supports microvilli in intestinal cells

- Intracellular traffic control for moving components around inside the cell

- Important component in muscle contraction

Front 25

Centrosome

Back 25

- Microtubule organizing center that contains a pair of centrioles (In plants, lack centrioles)

Front 26

Centrioles

Back 26

- Short cylinders of microtubules

- Not found in plant cells

Front 27

Peroxisome

Back 27

- Vesicle that is involved in fatty acid metabolism

Front 28

Polyribosome

Back 28

- String of ribosomes simultaneously synthesizing same protein

Front 29

Central Vacuole

Back 29

- Large, fluid-filled sac that stores metabolites and helps maintain turgor pressure

- Larger than vesicles to store materials that occur in excess

- Up to 90% volume of some plant cells

- Stores water, nutrients, pigments, waste products

- Stores toxic substances used for protection from herbivores

Front 30

Plasma Membrane

Cytosol

Chromosomes

Ribosomes

Back 30

4 Basic Features of ALL cells

Front 31

DNA to mRNA to proteins

Back 31

Central Dogma of Molecular Biology

Front 32

Ribosomes

Back 32

- Consists of a large and small subunit

- Comprised of rRNA

- Subunits are made in nucleolus

Front 33

Endomembrane System

Back 33

- Series of intracellular membranes that compartmentalize the cell

- Restricts enzymatic reactions to specific areas within cell

- Consists of Nuclear Envelope, Endoplasmic Reticulum, Golgi, Vesicles, Plasma Membrane

Front 34

Rough Endoplasmic Reticulum

Back 34

- Studded with ribosomes on cytoplasmic side

- Synthesizes proteins by modifying and processing proteins - adds sugar to proteins which results in glycoproteins

- Form transport vesicles so substances can move to Golgi

Front 35

Smooth Endoplasmic Reticulum

Back 35

- Synthesis of lipids as well as the site of various synthetic processes, detoxification and storage

- Forms transport vesicles so substances can move to Golgi

Front 36

Golgi Apparatus

Back 36

- Consists of flattened, curved vesicles

- Modifies proteins and lipids with "signal" sequences

- Receives vesicles from ER, after modification, prepares for shipment and packages proteins and lipids into vesicles

- Some remain in cell, some are secreted, some return to ER or merge with plasma membrane

Front 37

Lysosomes

Back 37

- Membrane bound vesicles that contain powerful digestive enzymes and are highly acidic to digest larger molecules into simple subunits and recycle cellular resources

- Produced by the Golgi

- Not found in plants

Front 38

Phagocytosis

Back 38

- When white blood cells engulf pathogens and digest them in their lysosomes

Front 39

Chlorophyll

Back 39

- Green photosynthetic pigment in chloroplasts

- Found only in inner membranes of chloroplast

Front 40

Thylakoids

Granum

Stroma

Back 40

_________________ in stacks are called _______________ which are encased by the fluid-like _____________ in chloroplasts

Front 41

Matrix

Cristae

Back 41

- Mitochondria numbers vary with metabolic activities and energy requirements of cells (Liver has as many as 1000)

- Surrounded by double membrane, the outer membrane is smooth, the inner membrane surrounds the semi-fluid substance____________ and is folded to form _____________.

Front 42

Matrix

Back 42

- Inner semi-fluid substance containing respiratory enzymes in mitochondria

- Contains ribosomes and DNA