Name:
Guided Notes Chapter 7 Sections 1 - 4
Cell Structure and Function
Cells are the basic unit of
and
unit of living things.
English scientist named
made a simple microscope. He observed small, box-shaped
structures, called cellulae (meaning
)
Cell Theory
* All living things are made of one or more
* Cells are the basic unit of
and
things.
* All cells come from
cells.
Eukaryotic vs. Prokaryotic Cells
Eukaryotic cells contain DNA in the
region called the
.
.
in the organization of living
. Prokaryotic cells contain DNA in a concentrated
Basic Structure of every Organism
Based on 1 of 2 types of cells
Prokaryotic
‘pro’ =
‘karyon’ =
Eukaryotic
‘eu’ =
‘karyon’ = kernel
Basic Structure of every Organism
* Based on 1 of 2 types of cells
.
- Only exist in domains of Bacteria or Archaea
.
- Protists, fungi, animals, and plants
Basic Common Feature of Both
* Bound by selective barrier (
)
-Have cytosol (jellylike substance) - Where organelles and other components are found
* Contain
-Carry genes in the form of DNA
* Have ribosomes
Different Features of Both
Location of DNA
Eukaryotes
- Most DNA is in
(Nucleus is bound by double membrane)
Prokaryotes
-DNA is concentrated in region not membrane-enclosed called a
Cytoplasm
Eukaryotes
- Region between the
- Contains a variety of
Prokaryotes
- Interior of prokaryotic cell
and plasma membrane
of specialized form and function
Organelles
Eukaryotes
- Membrane- bound
- Specialized form and function
Prokaryotes
-Absence of organelles
are Present
Name:
Guided Notes Chapter 7 Sections 1 - 4
Size
Eukaryotes
-Generally
than prokaryotes
–
um in diameter
Prokaryotes
- Smallest cells known
–
um in diameter
Plasma Membrane
.
- a selective barrier (semipermeable) that allows passage of enough oxygen,
nutrients, and wastes to and from the cell.
The plasma membrane is a lipid bilayer embedded with diverse proteins.
Fluid Mosaic Model
.
- membrane is a fluid structure with a “mosaic” of various proteins embedded in or
attached to a phospholipid bilayer. (lipids and proteins are amphipathic)
Organelles
Nucleus: Information Central
.
- contains cellular DNA which includes most of the genes in the cell. The nucleus is
surrounded by the
.
.
- structures that carry genetic information (DNA). Each chromosome contains one
long DNA molecule.
Each eukaryotic species has a distinct number of chromosomes.
.
- the complex of DNA and protein making up chromosomes.
.
- helps synthesize rRNA (ribosomal RNA) and ribosomes.
Ribosomes: Protein Factory
.
- made of rRNA and proteins- carry out protein synthesis.
Ribosomes exist as either
ribosomes (suspended in cytosol) or
ribosomes (attached to the Rough ER or nuclear envelope)
Endoplasmic Reticulum: Biological Factory
.
- consists of membranous tubules, and sacs, called cisternae.
.
- lacks ribosomes. Functions lipid synthesis, detoxification, and storing calcium
ions.
.
- has ribosomes on surface. Continuous with the nuclear envelope. Synthesizes
glycoproteins and other secretory proteins.
Golgi Apparatus: Shipping and Receiving
.
- made of flattened membranous sacs called cisternae. Has 2 sides the cis face
(receiving) and the trans face (shipping).
Lysosomes: Digestive Compartments
.
- contains hydrolytic enzymes used to digest molecules.
.
- “cell eating”- lysosome digesting food
Vacuoles: Storage Centers
.
- store food and water for the cell
Mitochondria: Chemical Energy Supercenter
.
- site of cellular respiration.
.
- the process that uses O2 to generate ATP by extracting energy from sugars, fats,
and other fuels.
Name:
Guided Notes Chapter 7 Sections 1 - 4
Chloroplast: Light Energy Capturer
.
- found in plants and algae- the site of photosynthesis. Contain the green pigment
chlorophyll.
Is a member of the plastid family- a group of plant organelles.
Peroxisomes: Oxidation
.
- contain enzymes that remove hydrogen atoms and transfer them to oxygen,
producing hydrogen peroxide (H2O2).
Cytoskeleton
Cytoskeleton
.
- a network of fibers extending throughout the cytoplasm- plays a major role in
organizing the structure and activities of the cells.
.
- allows for cell movement.
.
- the thickest cytoskeletal fiber, provide a track that organelles with motor proteins
can move along. Help separate chromosomes during mitosis. Form flagella and cilia.
.
- region where microtubules are organized. Contains a pair of centrioles. Only in
animal cells.
.
- the thinnest fiber. Actin and myosin filaments help muscle cells contract.
Aide in pseudopodia movement by converting cytoplasm from a liquid to a gel.
.
- more permanent fixtures, fix the position of organelles and shape of the cell.
Include keratin proteins.
Cell Wall
.
- extracellular structure of plant cells. Protects the cell, maintains its shape, and
prevents excessive uptake of water. Holds the plant up against gravity.
Passive Transport
.
- moves solute from high to low concentration. DO NOT requires energy.
Diffusion
.
- type of passive transport in which there is a movement of molecules of any
substance until they spread out evenly in the available space. (equilibrium).
Diffusion is a spontaneous process, needing no energy input.
Rule of Diffusion: in the absence of a force, a substance will diffuse from high concentration to low
concentration.
A substance diffuses
other substances.
Osmosis
.
its own concentration gradient, unaffected by the concentration of
- Type of diffusion. Diffusion of water
.
- the ability of a surrounding solution to cause a cell to gain or lose water.
.
- concentration of solution is more than the cell. Cell will lose water, shrivel, and
probably die.
.
- concentration of solution is less than the cell. Water will enter the cell and the cell
will swell and lyse (burst).
.
- concentration of solutions is the same on both sides of the membrane. No net
movement of water = stable volume.
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Guided Notes Chapter 7 Sections 1 - 4
Facilitated Diffusion
.
- passive transport aided by proteins.
Frequently involves polar molecules.
.
- channel proteins that transport ions down the concentration gradient. No energy
required.
.
- open or close in response to a stimulus.
Active Transport
.
- moves solute from low to high concentration. Requires energy (usually ATP). Uses
carrier proteins.
Active transport allows a cell to have an internal concentration different from its surroundings.
Sodium – Potassium Pump
Sodium-Potassium Pump- an example of active transport that exchanges
for
across
the plasma membrane.
Endocytosis/Exocytosis
.
- the secretion of large molecules by the fusion of vesicles with the plasma
membrane. Requires energy.
.
- cell takes in molecules by forming new vesicles from the plasma membrane.