The document provides information about cells including:
1. It summarizes the cell theory which states that cells are the basic units of life, all living things are made of cells, and new cells come from existing cells.
2. It describes the two main types of cells - prokaryotic cells which lack a nucleus and organelles, and eukaryotic cells which have a nucleus and organelles.
3. It details several organelles found in eukaryotic cells and their functions including the nucleus, mitochondria, chloroplasts, endoplasmic reticulum, Golgi apparatus, lysosomes, and vacuoles.
2. The Discovery of Cells
• Robert Hooke (mid-1600s)
– Observed a sliver of cork with a hand-made microscope
– Saw a “row of empty boxes”
– Coined the term cell
3. Cell Theory
The Cell Theory states:
1. Cells are the basic units of life.
2. All living organisms are made up of one or more cells.
3. New cells can only come from already existing cells.
– no spontaneous generation
• Francisco Redi's
experiment:
6. Cell Size & Shape
• All cells have:
– a membrane
– cytoplasm
– DNA
7. Cell Types
• All living organisms are made up of cells.
– There are two major cell types:
PROKARYOTIC Cells
– All bacteria and archaebacteria
– Lack a nucleus
– Lack membrane-bound organelles
EUKARYOTIC Cells
– Plants, animals, fungi and Protists
– Have an enclosed nucleus
– Have membrane-bound organelles
10. Cell Organelles
• Organelle = “little tool”
• Organelles found only
inside eukaryotic cells
• Watery stuff between
the organelles is cytosol
• Area inside a cell is the
cytoplasm
– includes the organelles
but NOT the nucleus
11. Cell Membrane
Cell Membrane
• Boundary of the cell
– a.k.a plasma membrane
• Holds cell contents together
• Semi-permeable:
acts like a filter or
screen
– some things pass
while others cannot
12. Cell Membrane
• Made of a phospholipid bilayer
Semi-permeable:
A few molecules
move freely across
the membrane
(in and out of the cell)
• water
• carbon dioxide
• ammonia
• oxygen
Other molecules need the help of
transport proteins to get across
13. Nucleus
• Easiest cell structure to see
under a microscope
• Contains chromatin
– genetic material including
DNA, RNA and proteins
– form chromosomes
• “Control center of the cell”
14. Nucleus
• Surrounded by a double
membrane
• Nuclear Pores
– holes in membrane allow
material to enter and leave
the nucleus
• Nucleolus is an area of
concentrated RNA
15. Endoplasmic Reticulum
• Abbreviated “ER”
• Connected to nuclear
membrane
• “Highway of the cell”
• Smooth ER
– makes lipids
• hormones, steroids,
some vitamins, etc.
• Rough ER
– studded with ribosomes
– makes proteins
17. Golgi Apparatus
• Looks like a stack
of pancakes
• Stores, sorts,
modifies and
packages proteins
• Molecules
transported to
and from the
Golgi by means of
vesicles
18. Lysosomes
• "Garbage disposal
of the cell"
• Contain hydrolytic
enzymes that break
down food & wastes
• Destroy old cell
parts as well as
invaders
• Formed from the
Golgi apparatus
19. Mitochondria
• “Powerhouse of the cell”
• Cellular respiration occurs
here to convert and release
energy for the cell to use
• Has its own DNA and
ribosomes
• Folded parts called cristae
increase surface area
23. Cell Wall
• Found in plant and
bacterial cells
• Rigid, protective
barrier composed of
cellulose fibers
• Located outside the
cell membrane
24. Chloroplast
• Found only in plant cells
• Contains the green
pigment chlorophyll
• Site of food (glucose)
production known as
photosynthesis
• Contains own DNA and
replicates independently
27. Week 5 Lab
Review
Intro to Microscopy
Laboratory Science as a Career
28. Cytoskeleton
• Microfilaments and
microtubules provide
a scaffolding on which
organelles can anchor
or move themselves
– contracting muscles
cells
– dividing cells pinch in
half
– waving cilia and
rotating flagella
29. Cilia & Flagella
• Hair or tail-like
structures that provide
motility (movement)
• Formed from
microtubules that
arrange themselves
into centrioles
• Generally occur only in
animal and bacteria
cells
30.
31. Peroxisomes
• Small sacks enclosed in a
single membrane
• Contains enzymes that
break down fatty acids &
toxic peroxides (found in
alcohol, formaldehyde, and
other poisons)
• Found mostly in kidney and
liver cells
• Formed from budding off
the ER
33. Quick Review
• Which organelle is the "control center" of the cell?
nucleus (containing DNA, the blueprints)
• Which organelle holds the cell together?
plasma membrane (made of a phospholipid bilayer)
• Which organelles are NOT found in animal cells?
cell wall (and capsule), chloroplasts, large/central vacuole
• Which organelle helps plant cells make food?
chloroplasts (via photosynthesis, using chlorophyll)
• What does E.R. stand for?
endoplasmic reticulum
34. This cell has no clear nucleus, but it does have a CELL WALL.
Is it prokaryotic or eukaryotic?
39. Careers in Laboratory Science
• Researcher
– PhD or MD/PhD
– Design experiments, publish
conclusions
– Apply for grants, hire staff
• Research Assistant
– Manages experiments
– Assists with data collection, data
entry, and statistical analysis
• Medical Lab Tech
– Run lab tests and reports data
• research or medical treatment
• Forensic science
• genetic counseling
• Pharmaceutical Production & Sales
– Requires business skills & knowledge of chemistry and human
physiology
Notes de l'éditeur
Anton van Leeuwenhoek, a Dutch scientist in the mid-1600s, was the first to record looking at water under a microscope. He found that water was full of living things.
Italian physician Redi disproved spontaneous generation. Others observed maggots crawling out of meat and assumed the dead cow meat gave rise to baby flies. By performing this experiment, Redi disproved that theory and sought another explanation: that flies lay eggs on the meat, which only provides the food maggots need to survive. The source of the baby fly larvae is, therefore, not the dead meat, but the living fly parents. Experiment 1: Meat was placed in an unsealed jar. Observation: Flies laid eggs on the meat and maggots emerged. Experiment 2: Meat was placed in a sealed jar. Observation: Flies could not enter the sealed jar and therefore, maggots did not form on the raw meat. Experiment 3: Meat was placed in a jar covered with gauze. Observation: The gauze prevented flies from entering the jar, and therefore, maggots did not form on the raw meat. Conclusion: Maggots arise from the eggs laid by flies, not by spontaneous generation. This supported the theory of biogenesis, which states that "all life arises from other life."
Some of Pasteur's flasks, still free of microorganisms, are at the Pasteur Institute in Paris.
What benefits could there be to having distinct organelles separated by membranes? Chemical reactions which interfere with each other can occur at the same time.
This is an actual microscopic image. Colors are added digitally to enhance the different parts.
E. Coli
Animal (liver) cell
Personal experience - U of P, mice stress-immune response - Good Sam, sleep lab/EKG - OHSU, melatonin research