Transcript Cells – The Basic Unit of Life - Belle Vernon Area School District

Cells – The Basic Unit of Life
A. Smallest unit that has ALL the
characteristics of life
1. Grow
2. Respond to a stimuli
3. Reproduce
4. Metabolism
5. Move
6. Homeostasis
B. Several types of cells
1. Variety of shapes
2. Variety of sizes
Cell structure determines function
Cell function determines structure
C. Functions of the cell
1.
2.
3.
4.
5.
Basic unit of life
Protection & support
Movement
Communication
Cell metabolism & energy release
D. 70 – 80% Water
E. Two areas of water
Intracellular-inside the cell
Extracellular- outside the cell
1. Extracellular
►Thick, syrup-like liquid
►Mixture
of dissolved gases, salts, food &
cellular products manufactured or
synthesized by mechanisms inside the
cell, which leave by secretion.
ex. hormones, vitamins, & proteins
Types
A. Contained within blood vessels &
chambers of the heart
Plasma -liquid medium for transport
(Oxygen, wastes, &
nutrients).
B. Interstitial Fluid
Pathway for products that are in route
between cells.
C. Extracellular Matrix---ECM---composed of
proteins and polysaccharides
Purpose of ECM- Structural support
for the body
Other Functions
2. Intracellular Environment
Between Cells
►Protoplasm or Cytoplasm
►
Components –
Water
Fats
Proteins
Nucleic Acids
Carbohydrates
Electrolytes
When the components are organized in such a
way you get:
Characteristics of life
Boundary of the cell or Cell (Plasma)
Membrane
► 3 major components inside the cell
1. Intracellular fluid - cytoplasm or
protoplasm
2. Organelles - small membrane bound
vessels
3. Nucleus - regulates the cell activities
Review
► Name
three characteristics of life?
► How
is intracellular material different from
extracellular material?
► How
is interstitial fluid different from
extracellular fluid?
II. Cell Membrane
A. Bilipid layer
1. Composed of two phosolipids layers
2. Glycoproteins
3. Proteins
a. Integral
b. Peripheral
4. Cholesterol
5. Glycolipids
6. Membrane receptors
7. Carrier molecules
8. Receptor molecules
B. Fluid Mosaic Model
C. Semi Permeable- Selective permeable
Not everything can pass through the cell
membrane.
2. Materials that pass with ease
a. Water
b. Small lipid soluble molecules
c. Small non charged particles
3. Materials that have difficulty passing:
a. Larger molecules
(lipid soluble or non lipid soluble)
b. Charged particles
c. Need carrier proteins to pass
through the cell membrane.
4. Two ways materials can pass through the cell
membrane
a. Passive – no energy required
Following a concentration gradient from high to
low to establish equilibrium.
Majority of life’s process.
b. Active – requires energy
Going against the concentration gradient trying NOT
to establish a equilibrium
Nerve cells
5. Ways that material can pass through
the cell membrane.
a. Directly
b. Membrane channels
c. Carrier molecules
d. Vesicles
Review
► Describe
the structure of the cell
membrane.
► What function does it perform?
► How do lipid-soluble molecules, small
molecules and large molecules that are not
lipid base cross the cell membrane?
► How is passive movement different from
active movement?
D. Types of Passive movement
1. Simple Diffusion - Following a
concentration gradient from high to
low to establish equilibrium.
Small lipid soluble & Non charged
particles
2. Facilitated Diffusion
Following a concentration gradient
from high to low to establish
equilibrium.
Larger & charged particles
Need Carrier proteins
3. Osmosis – Diffusion of water across a semipermeable membrane.
a Types of osmosis
1. Isotonic Solution –
Equal movements of water into and out of the cell
due to equal solute concentrations.
2. Hypertonic –
More movement of water out of the cell then in due
to more solutes out of the cell.
3. Hypotonic –
More movement of water into the cell then out due
to more solutes in the cell
Review
How is simple diffusion different from
facilitated diffusion?
What would happen to cells that are placed in
the following solutions:
isotonic, hypertonic, hypotonic.
E. Active transport
Requires energy - ATP
Going against the concentration
gradient trying NOT to
establish
equilibrium
Ex. Sodium – Potassium
Pump
F. Cytosis – Movement of molecules across the cell
membrane by forming a vesicle and requiring ATP.
1. Two types
a. Exocytosis –
Materials leaving the cell.
b. Endocytosis – Materials entering the cell.
1. Phagocytosis –
Engulfing large solid particles
“cellular eating”
2. Pinocytosis – Engulfing liquids.
“cellular drinking”
Movement of Materials Review
Review
► How
are facilitated diffusion and active
transport similar and how are they
different?
► How
are phagocytosis, pinocytosis,
endocytosis, and exocytosis similar and how
are they different?
III. Cytoplasma and Organelles of the cell.
A. Cytoplasma – between the cell
membrane & nucleu
1. Cytosol
a. water
b. proteins
c. organic compounds
d. inorganic compounds
2. Organelles
small compartments that do a particular
function
B. Types of organelles
1. Endoplasmic reticulum (ER) – series of
membrane folds
a. Two types
Rough (ER) – Hold ribosomes – protein
production
Smooth (ER) – No ribosomes – Lipid synthesis
(hormones), detoxification.
2. Golgi Body –
series of membrane folds
Packaging and shipping of proteins
3. Mitochondria –
a. Produces energy for the body in the form of
ATP.
b. Two lipid membranes.
1. Inner – Cristae
2. Space – Matrix
c. Own DNA
4. Lysosomes – Contain enzymes to break apart
intracellular particles.
5. Peroxisomes – Contains enzymes to detoxify only
in the presence of oxygen.
6. Nucleus – “Control center”
a. Round.
b. Largest part of the cell.
c. Contains genetic material of the cell DNA &
RNA.
d. Components
1. Nuclear membrane
* bilipid layer
* pores for movement
2. Nucleoplasm – similar to cytosol
* Nucleoli – composed of RNA and proteins.
* Chromatin
-Thin strands of DNA wrapped around
proteins balls called histones.
-Contains genes
7. Cytoskeleton – proteins that support the cell, hold
organelles & allows the cell to change shape.
Microtubules – hollow structure made of protein
sub-unit. (large)
1. Cell division
2. Form flagella & cilia
3. Cytoskeleton
Microfilament - cellular movement.
Filaments(small)
Intermediate – Filaments (between)
Ex. Centrioles – helps the cell with cellular division.
8. Cilia
9. Flagella
10. Microvilli
Organelle Review
Organelle Review
Review
► What
is the
organelles:
golgi
SER
RER
function of the following
ribosome
mitochondria
cilia
flagella
Why is the nucleus referred to as the “control
center” of the cell?
IV. Protein Synthesis
A. Genetic Code
1. Based on the genetic code.
2. Code from your DNA which
contains genes.
3. DNA is made up of nucleotides.
4. Nucleotides are in groups of three
– codons.
B. First Step in Protein synthesis
1. Transcription
a. Copying DNA into RNA
b. Protects the master copy
2. Three type of RNA
a.Messenger RNA – mRNA
mRNA Contains the message on how to make the protein.
b. Transfer RNA - tRNA
Transfers the AA to build the protein.
- Contains anticodons.
c. Ribosomal RNA – rRNA
Site of protein production
Composed of large and small subunits.
C. Second Step in Protein Synthesis
1. Translation
a. Copying RNA into Proteins
b. Requires all the types of RNA
2. Steps
1. mRNA binds to rRNA
2. The two subunits come together.
3. tRNA with the AA must match up the
ANTICODON to the CODON of the mRNA.
4. Process repeats and peptide bond forms
between the AA until the entire protein is
produced.
Transcription, Translation Review
Review
► What
is a gene?
► What
process do the cell copy DNA into
RNA? Why?
► What
role does mRNA play in transcription?
V. Cell Division
A. Two types
1. Mitosis – Nuclear division
a. Exact copies of cells are produced.
b. Purpose
1. Growth
2. Maintenance
3. Repair
c. Diploid to diploid.
d. Stages
1. Interphase – cells grows. DNA duplicates.
2. Prophase – Nuclear membrane breaks down.
Centrioles move to opposite poles. Chromosomes
form.
3. Metaphase – Chromosomes line up at the cells
equator.
4. Anaphase – Chromosome separate
5. Telophase – Reverse of prophase.
6. Cytokinesis – Cytoplasm and organelles divide
Mitosis
2. Meiosis – Gamete production
a. Cells are no longer exact copies.
b. Diploid to haploid.
c. Purpose
1. Sexual
reproduction
1. Interphase
2. Prophase I
3. Metaphase I
4. Anaphase I
5. Telophase I
6. Interkineses
7. Prophase II
8. Metaphase II
9. Anaphase II
10. Telophase II
VI. Cellular Aging
A. Cellular Senescence
1. Irreversible changes within the cell.
a. Graying
b. Wrinkles
c. Accumulation of body fat
d. decreased muscle tone
e. Loss of agility
f. Slowing of mental ability.
B. Two theories on aging
1. Genetic – RUN OUT OF GAS
2. Environmental – FREE RADICALS.