Transcript Cells - Faculty Sites

ANATOMY AND PHYSIOLOGY I
BIOS 2310
Instructor: Sarah Jeffers
Additional Information
• Syllabus
• Typical schedule with resources
• Student email
• Media Share – find one peer reviewed article/video to share with
your classmates. You must also comment on someone’s.
• Helpful websites:
• http://faculty.mccneb.edu/sajeffers
• http://www.quia.com/pages/sjeffers53/bios2310
Unit I: Organization
Cells
Chapter 3
pp. 87-103
Levels of Biological Organization
• A characteristic of all living things is organization.
• Thus the name of all living things as organisms.
The Organ System Level
The Organ Level
The Tissue Level
The Cellular Level
The Chemical (or Molecular) Level
Atoms
Molecule
Organelle
Figure 1 Section 2
Levels of Biological Organization
Natural tendency is towards entropy.
All organisms consist of one or more cells
The cell is the simplest structural and functional unit of life.
Cells are the building blocks of all
plants and animals.
.
All new cells come from the division
of pre-existing cells.
Cells are the smallest units that perform
all vital physiological functions.
Nutrients
Division
O2
Wastes
Cell
Growth
New
cells
The cell theory
CO2
Cell Structures
Peroxisome
Lysosome
Microvilli
Golgi apparatus
Major Components:
Centrosome
Cell membrane
Nucleus
Nucleus
ECF
Cytoplasm/ICF
Organelles
Smooth endoplasmic
reticulum
Rough endoplasmic
reticulum
Ribosomes
Plasma
membrane
Cytoskeleton
Mitochondrion
Cell Membrane
• defines the boundaries of the cell
• controls passage of materials
• interaction with other cells
• composed of lipids (98%)
EXTRACELLULAR FLUID
Glycocalyx
(extracellular
carbohydrates)
Integral protein
with channel
Cholesterol
Phospholipid
Integral
glycoproteins
CYTOPLASM
Peripheral proteins
Cell Membrane
• other 2% is of proteins
• reception of chemical messages
• allows for pores for fluid and electrolyte
exchange
• adherence of adjacent cells to one another
• recognition of one cell by another
Cell Membrane
Surface extensions:
• Microvilli – increase a cell’s surface area, best used
for absorption; made of microfilaments; finger-shaped
• Cilia – hairlike, nearly every human cell has one
nonmotile (sensory); propels fluids or solids across
surface
• Flagella – whiplike, longer than cilia, sperm cell
Nucleus
• largest organelle
• cells can have 0 – 50 nuclei
• double membraned
• nuclear envelope with nuclear pores
• nucleus contains:
chromatin – DNA
nucleolus – synthesizes ribosomes
• maintains genetic material
ORGANELLES
Endoplasmic Reticulum
• synthesis of secretory products; intracellular storage and transport,
synthesis of cell membrane
• Rough ER – modifies and packages newly synthesized proteins
•Smooth ER – detoxifies alcohol and drugs; synthesizes lipids and
carbohydrates
Nuclear
envelope
ORGANELLES
Cytoskeleton
• collection of protein filaments
and cylinders
• cellular scaffolding within the
cell
• Determines shape & support
• move substances through the cell
ORGANELLES
Cytoskeleton
Microvilli
Cytoskeleton is composed of:
Microfilaments
• microfilaments –
– Actin
Secretory
vesicle in
transport
Lysosome
– Cell motility
Microtubule
Intermediate
filaments
• intermediate filaments –
– Keratin
– Resist stress
• microtubules –
Microtubule
in the process
of assembly
Microtubule
Undergoing
disassembly
Nucleus
Mitochondrion
(a)
– Tubulin
– Movement
(b)
15 m
ORGANELLES
Mitochondria
• “powerhouse cell”
• Chemiosmosis
• Diffusion of H+ ions across
membrane to create ATP
•Double membraned
• Cristae
ORGANELLES
Ribosomes
• Small granules of protein and rRNA
• Typically found as two separate subunits
• located in the nucleoli, nuclear envelope, and rough ER
• read coded genetic messages
• assemble amino acids into proteins – protein synthesis
ORGANELLES
Golgi Apparatus
• site of protein modification
• golgi vesicles package
protein, some become
lysosomes, some store
proteins for later use
ORGANELLES
Vacuoles
Lysosomes
• produced by the Golgi Apparatus
• digestive enzymes
• Functions:
– autophagy – digestion of
worn out organelles
– autolysis – “programmed cell
death”
ORGANELLES
Vacuoles
Peroxisomes
• not produced by the Golgi
Apparatus
• Function: neutralizes free
radicals, detoxifies alcohol &
drugs
– oxidize organic molecules
with molecular oxygen
– produce hydrogen peroxide
– excess is broken down to
water and oxygen by
catalase
An Analogy
Cells can be thought of as factories.
• cell membrane – shipping and receiving
• nucleus – engineering department
• ribosomes – assembly line
• Golgi apparatus – puts the finishing touches on
• vesicles - packaging
Cells
Cells are organized into tissues -
Group of cells and cell products
specialized for a particular
function.