Cell Biology
EXAM 1
Chapter 1
Cells were the universal building blocks of all living tissues.
3 Theres relevant to the understanding of the
... [Show More] fundamental principles of the cell:
The Cell Theory:
- Cells are the fundamental and functional units of life.
- A cell is the structural unit of life.
- All organisms are made of cells.
- All cells arise from preexisting cells.
(helps explain commonality found in cells and living tissues)
Theory of Evolution:
- random variation and natural selection can drive the production of organisms
with novel feature
- explains how diversity has arisen from organisms that share a common
ancestry.
(helps explain diversity found in cells)
Endosymbiotic Theory:
- process that certain organelles, notably mitochondria and chloroplasts,
originated as bacterial symbionts within a nucleus-containing host cell.
Chloroplast and mitochondria contain their own DNA and ribosomes.
Chloroplast and mitochondria contains inner and outer membranes. Outer membrane used to
belong to the blob cell and kept their own one.
Mitochondria and Chloroplasts originated from prokaryotic cells.
Lecture 2
Cell:
small membrane enclosed unit filled with a concentrated aqueous solution of
chemicals and endowed with the ability to reproduce.
Properties that define Life:
1. highly organized and order
2. display homeostasis
3. response to stimuli
4. take energy from environment and transform it
5. show adaptation to environment
6. growth and reproduction.
To really understand you have to understand what happens in the subatomic level.
Viruses (non living) lacks the ability to reproduce. It requires a host cell to reproduce.
Are all cells alike or different?
Diversity:
appearance and function, chemical requirements and activities.
Ex. A sulfur bacterium gets energy from H2S
Protozoans exemplifiy diversity.
Commonality:
similar basic chemistry, elements that make up all cells. C,H,O,N,
follow the same general processes.
- Advantage for having commonality:
- use of model organism to understand molecular functions of cells.
- Ex. Escherichia coli, Saccharomyces cerevisiae, Arabidopsis thaliana
Types of cells: Prokaryotes vs. Eukaryotes:
Prokaryotes: Domains: bacteria and archaea, unicellular, can merge together to form
colonies.
Eukaryotes: Domain eukarya: plants, animals, protist, fungi, mutlicellular, exception
yeast is a unicellular eukaryote.
NOT ALL BACTERIA IS BAD!!
Probiotics: good bacteria that can improve your health.
-Prokaryotic Cell
Single closed compartment
No membrane bound organelles (nucleus = membrane bound)
Lack defined nucleus+ DNA in nucleoid
All Cells have: DNA, plasma membrane, ribosome, and cytosol.
- Cells are small, water, colorless. Use of dyes and stains allows them to be seen.
1. Light microscope interference- Contrast Optics
- using difference in refractive index among organelles.
- cant see anything smaller than 0.2 um. (limitation of light)
1. Confocal Microscopy
- multiple fluorescent probes can be used in a single cell
3. Transmission Electron Microscope: (TEM)
- Details on the inside of the cell can be seen, large molecules, DNA can be
seen.
4. Scanning Electron Microscope: (SEM)
- structural details on the surface.
Ex Trichomes: A. Thaliana [Show Less]