Download Eukaryotic cells have internal membranes that compartmentalize

Eukaryotic cells have internal
membranes that compartmentalize
their functions
Maria Agapito, PhD
Class Objectives
Upon completing this lesson you will:
• To determine what is the basic structural and functional unit of an
organism
• To describe what type of cells belong to each evolutionary domain
• To learn the names of the organelles and function of a cell
• To be able to draw or write out your own model or metaphor to
demonstrate the parts of a cell (Using your BHSEC school)
• To recall lecture information active learning exercise (Jeopardy
style)
How cells fit into the rest of the body’s organization
Cell
Tissue
Organ
Organ
System
Organism
What is the structural and functional unit of an
organism?
Cells
= are the basic structural and functional units of every organisms
Two distinct types:
Prokaryotic Cell = Bacteria and Archaea
Eukaryotic Cell = Protists, fungi, animals
and plants
Similarities in Prokaryotic and Eukaryotic cells
Plasma
Membrane
Selective barrier
Cytosol
Semifluid, jellylike substance
Chromosomes
Carry genes in the form of
DNA
Ribosomes
Tiny complexes that make
proteins according to
instructions from the gene
Differences in Prokaryotic and Eukaryotic cells
Location of DNA
Prokaryotes
Eukaryotes
Before nucleus
True nucleus
Nucleoid
Nucleus
Cytoplasm
Non-membrane
Bound structures
Size
.10 – 5.0 μm
Membrane
Bound structures
10 – 100 μm
Plasma membrane: Cellular metabolism and Limits on cell size
Allows passage of enough
oxygen, nutrients, and
wastes to service the
entire cell
Thus, for every second – only a
limited amount of a particular
substance can cross the cell
membrane
Cellular metabolism and Limits on cell size
1. As a cell increases in size, its volume
grows proportionally more than its surface
area
Area is proportional to a
linear dimension squared
Volume is proportional to
the linear dimension
cubed
25X
125X
The need for a surface area sufficiently large to
accommodate the volume helps explain the size
and shapes of most cells.
Why is the ratio of surface area to volume so critical for cell function?
Cellular metabolism and Limits on cell size
2. A sufficiently high ratio of surface area to volume is
especially important in cells that exchange a lot of
material with their surroundings
Q: Do larger organisms have larger cells than smaller organisms?
A: No, instead the larger animals have more cells
5X
How is a cell like a city?
Newark , New Jersey
Cellular Organelles overview
Prokaryotic Cell Structures
A Prokaryotes cell lacks a true nucleus and other membrane bound
organelles, simpler in structure
Prokaryotic Cell and Diseases
Peptidoglycan
Streptococcal
infections = Sinusitis,
Strep throat,
pharyngitis
Lyme disease = Borrelia
burgdorferi
Syphilis = Treponema
pallidum
What is the Antibiotic commonly used for these infections?
What is the Antibiotic Mechanism of action?
Penicillin
Disrupts the synthesis of the
peptidoglycan layer of
bacterial cell walls.
Eukaryotic Cell - Animal
4A
2
1
4B
4C
5
How is a cell like a city?
Comparing Animal versus Fungi cells
Animal cells lack:
Cell wall
Vacuole
Comparing Animal versus Plant cells
Plants cells lack:
Lysososomes
Centrosomes with centrioles
Flagella (but present in some plant sperm)
Eukaryotic Cell - Plant
Comparing Plant versus Protists cells
Plant cells similarities:
cell wall
Vacuole
Chloroplast
The eukaryotic cell’s genetic instructions are housed
in the nucleus and carried out by the ribosomes
What does this mean?
Nucleus versus ribosomes
NUCLEUS
Houses most of the cell’s DNA material. contains most of the
genes but some are located in the mitochondria and
chloroplast
RIBOSOMES
Uses information from the DNA to make proteins
The nucleus: Information central
Encloses the nucleus, separating it contents from the cytoplasm
Nuclear envelope – continuous membranes
Granules and fibers adjoining part of the
chromatin
Lines each pore, regulates the entry and exit of
proteins, macromolecules and RNA’s
rRNA synthesis occur here and it
requires DNA instructions
Proteins imported from the cytoplasm
are assembled with rRNA into large and
small subunit of ribosomes
These subunit of ribosomes will
eventually assemble in to a ribosome =
protein synthesis machinery . Process
will begin upon contact with a mRNA
molecule in the cytoplasm
Maintains the shape of the nucleus
by supporting the nuclear envelope
The nucleus: Information central
Complex of DNA and proteins making up a chromosome
Carries the genetic information
DNA is organized into chromosomes
A somatic versus a gametes cell
46 chromosomes
23 chromosomes
Ribosomes – Protein factories
Protein Synthesis can occur in
two cytoplasmic locations:
1
2
A complex of rRNA
and proteins that carry
protein synthesis
Free ribosomes protein synthesis = Proteins function within
the cytosol EX: enzymes that catalyze sugar breakdown
Bound ribosomes protein synthesis = Proteins are destined
for insertion into membranes, for packaging within certain
organelles. EX: lysosomes
EX: Pancreas – secrete digestive enzymes
How is a cell like a city?
Cell membrane
Ribosomes
Golgi Bodies
Mitochondria
CHLOROPLAST
CHLOROPLAST
Lysosomes
ER
Mitochondria
Vacuole
Nucleus
What type of cell will this be? Animal or Plant
Plant