LESSON 1b: OVERVIEW OF THE CELL Flashcards
More than _____ cell types identified in human body
200
4 basic tissue types
- Epithelia
- Connective Tissue
- Muscle
- Nervous Tissue
Specialized Cell Types
- Rod cells -Photoreceptor Cells
- Hair Cell- Sound Receptor
- Germ cell- sperm
- Red Blood Cells
- A cell must be large enough to house DNA and organelles it needs to survive and reproduce
- It must be small enough to obtain nutrients from the environment and dispose of wastes
Natural laws limit cell size
A cell must be large enough to house _______ and ________ it needs to survive and reproduce
DNA and organelles
Smallest Bacteria
Mycoplasmas (0.1 to 1.0 micron)
It must be small enough to obtain _________ from the environment and dispose of_____
-nutrients
- wastes
Lower limit of most bacteria
1-10 micron
Upper limit of eukaryotic cells
10- 100 microns
- ‘smaller parts within larger cells’
- organization of parts into smaller units (Organelles) within the cell
- Increased surface area, better specialization
Compartmentalization
- In-folding of cell membrane formed organelles such as ER, golgi etc
- Followed by specialization of functions ( transport, ingestion etc)
In-folding and Specialization
Compartmentalization
A step in cellular evolution
Advantage of having internal membrane
increase efficiency
Endosymbiotic theory
- Archaeal cells acquire eukaryotes features
- Bacteria establish symbiosis with host
3.1 Endosymbiont evolves into mitochondrion
3.2 Engulf cyanobacterium, cyanobacterium evolves into chloroplasts.
Example of Cellular Evolution
- In-folding and Specialization
- Development of Internal Membranes
Create internal micro-environments (“compartments”)
Internal Membrane
-Ribosomes are present
-mainly near cytoplasm
-occurs form the nuclear membranes
-main component is cisternae which appear more maze
- function in synthesis and storage of proteins
Rough ER
In the _____________ the ancestral eukaryote consumed aerobic bacteria that evolved into mitochondria
First endosymbiotic event
others cells evolved through a symbiotic relationship where one organism lives inside another
Endosymbiosis
-Lacks attached ribosomes and appears more tubular.
-Gives the cell the ability to perform variety of specialized functions
- Functions in the synthesis of lipids, carbohydrate metabolism and detoxification
Smooth ER
Interesting evolution of Mitochondria, Chloroplast & Bacteria includes evolution in:
-Membrane
-Antibiotics
-Division
-DNA
-Ribosomes
Interesting evolution of Mitochondria, Chloroplast & Bacteria Evidences: indicates organelles may have bacterial origin
Susceptible to Antibiotics (e.g. chloramphenicol)
Interesting evolution of Mitochondria, Chloroplast & Bacteria Evidences: Some organelles have double _______________. (Outer Membrane may be vesicular in origin)
Membrane
Interesting evolution of Mitochondria, Chloroplast & Bacteria Evidences: Reproduction occurs via a fission-like process
Division
Interesting evolution of Mitochondria, Chloroplast & Bacteria Evidences: Has own ____ which is naked and circular (like prokaryotic DNA structure)
DNA
Interesting evolution of Mitochondria, Chloroplast & Bacteria Evidences: Have _____ which are 70s in size
Ribosomes
Binary Fission in Mitochondria
Mitochondrial DNA/Cell—> Fission (Start na ang seperation)—> Segregation
The tree of life or the three domains of life is consist of:
-Archaea
-Bacteria
-Eukaryotes
Eukaryotes
less than 1mm
Prokaryotes
less than 1mm, greater than 1 micrometer
Proteins and Viruses (?)
less than 1 micrometer, greater than 1nm
Small molecules and atoms
less than 1nm
Archaea more related to _______ than ______
Eukarya than Bacteria
-> Single celled organisms
-> No nucleus, no compartments
-> Peptidoglycan cell walls
-> Binary fission
-> For energy, use organic chemicals,
inorganic chemicals, or photosynthesis
Prokaryotes – Domain Bacteria
-> Lack peptidoglycan
-> Live in extreme environments
Include:
Methanogens
Extreme halophiles
Extreme thermophiles
-> Role in disease not well understood—this
group has only recently been discovered
Prokaryotes – Domain Archaea
____________ growing in
Yellowstone hot springs
Thermophiles
Two Fundamentally
Different Types of Cells
Prokaryotes and Eukaryotes
A ____________ is enclosed by a plasma
membrane and is usually encased in a rigid
cell wall – The cell wall may be covered by
a sticky capsule
prokaryotic cell
___________ are partitioned into
functional compartments
Eukaryotic cells
Eukaryotes are distinguished by the
presence of a____________
true nucleus
DNA in nucleoid region
Prokaryotes
DNA within membrane-bound nucleus
Eukaryotes
Usually Smaller
Prokaryotes
Usually Larger
Eukaryotes
often multi-cellular
Eukaryotes
Usually Single-celled
Prokaryotes
may not need oxygen
prokaryotes
usually need oxygen to exist
eukaryotes
no membrane bound organelles
Prokaryotes
have membrane-bound organelles
eukaryotes
Plant and Animal Cells structural similarities
– Plasma membrane
– Genetic mechanisms
– Most organelles
Plant and Animal Cells structural differences
– Plants have choloroplasts, a large central vacuole and a cell wall
– Plant cells do not have centrioles
– Plant cells have plasmodesmata
– Animal cells have gap junctions
Plant and Animal Cells physiological differences
– Plant cells have photosynthesis in addition to respiration
– During mitosis a cell plate is formed in plant cells
– Starch is molecule for energy storage while in animal cells it is
glycogen
– Large central vacuole stores more water and carbohydrates then
animal cell vacuoles
Cell’s control center
Nucleus
Nickname: “Roads”
– Function: The internal
delivery system of the
cell
Endoplasmic Reticulum
- Synthesize proteins, carbohydrates, and lipids
- Stores molecules and materials
- Transports materials
- Detoxification of toxins
Endoplasmic Reticulum
- Sites of protein
synthesis - Composed of a
large and small
subunit - Types – Free
- move
through the
cytoplasm
– Fixed-Attached to
endoplasmic
reticulum
Ribosomes
Solar panel of the plant cell
Chloroplast
Only plants have chloroplasts, but ______ reap the benefits too.
animals
-Contain digestive enzymes
-Perform clean up and duties
-Digesting food or cellular invaders
-Recycling cellular components
Lysosomes
Worn out mitochondria may be an important factor in _________-.
aging
- In specialized zone near
nucleus: Centrosome - Each unit consists of
microtubules
– Support the cytoplasm
– Form certain organelles
– Responsible for cell
movement
– Involved in cell division
– Involved in transport of
intracellular materials. - Before cell division,
centrioles divide, move to
ends of cell and become
spindle fibers
Centrioles
- Flattened membrane sacs stacked on
each other - Modification, packaging, distribution of
proteins and lipids - Provides vesicles which become
lysosomes
Golgi Apparatus
Cellular Processes
-Cell Growth
-Cell Death
-Cell Movement
Cell Growth—>__________
Cell Division
Cell Movement–>Motility–>____________
Flagellum
Cell Death—>__________
Apoptosis
