2 Flashcards
Archea
Bacteria
Plant cells
Human cells
Cellular Diversity
More than _____ types identified in human body
200 cell
Arranged into tissues - ______ basic tissue types
4
4 basic tissue types
- epithelia
- connective tissue
- muscle
- nervous tissue
Specialised cell types:
- rod cells - photoreceptor cells
- hair cell - sound receptor
- germ cell - sperm
- red blood cells
Natural laws limit cell size
A cell must be ______ enough to house DNA and organelles it needs to survive and reproduce
large
Natural laws limit cell size
It must be ________ enough to obtain nutrients from the environment and dispose of wastes
small
Surface area
of one large
cube = _______
5,400 µm2
Total surface area
of 27 small cubes
= _____
16,200 µm2
A cell ________ infinitely small
cannot be
Limits to cell size
- smallest bacteria
- mycoplasmas
- 0.1 to 1.0
- most bacteria
- 1-10 microns
Lower limit
Limits to cell size
- eukaryotic cells
- 10-100 microns
Upper limit
- ‘smaller parts within larger cells’
- organization of parts into smaller units (Organelles) within the cell
- Increased surface area, better specialization
COMPARTMENTALIZATION
A step in cellular evolution
Compartmentalization
Cellular Evolution
In-folding of cell membrane formed organelles such as _________
ER, golgi etc
Cellular Evolution
Followed by specialization of functions such as ____
( transport, ingestion etc)
- create internal micro-environments (“compartments”)
- advantage = increase efficiency
Developmental of internal membranes
Differences Between Rough and Smooth Endoplasmic Reticulum
The rough endoplasmic reticulum (RER) has ribosomes on its surface, making it appear rough, and is primarily responsible for protein synthesis and processing. In contrast, the smooth endoplasmic reticulum (SER) lacks ribosomes, giving it a smooth appearance, and focuses on lipid synthesis, carbohydrate metabolism, and detoxification.
■ Smooth ER lacks attached ribosomes and appears more tubular than rough ER, where as the rough ER appeared as more of a maze.
■ Smooth ER gives the cell the ability to perform a variety of specialized functions.
■ Smooth ER functions in the synthesis of lipids, carbohydrate metabolism, and detoxification.
Smooth Endoplasmic Reticulum
Other cells evolved
through _______
Endosymbiosis
evolution through Endosymbiosis
- In a first endosymbiotic event, the ancestral eukaryote consumed aerobic bacteria that evolved into mitochondria.
- In a second endosymbiotic event, a descendant consumed photosynthetic bacteria that evolved into chloroplasts.
Some organelles have double membranes (outer membrane may be vesicular in origin)
Membrane
Susceptible to antibiotics (e.g. chloramphenicol) (indicates organelles may have bacterial origins)
Antibiotics
Susceptible to antibiotics (e.g. chloramphenicol) (indicates organelles may have bacterial origins)
Antibiotics
Reproduction occurs via a fission-like process
Division
Reproduction occurs via a fission-like process
Division
Has own DNA which is naked and circular (like prokaryotic DNA structure)
DNA
Have ribosomes which are 70S in size (identical to prokaryotic ribosomes)
Ribosomes
- Mitochondria similar to bacteria ( same size and shape as bacteria)
- With DNA as hereditary material
- Semi-autonomous
- Used to be bacteria
Mitochondria
The Tree of Life
EUKARYOTES
PROKARYOTES
VIRUSES??????
PROTEINS
SMALL MOLECULES
AND ATOMS
Three Domains of Life
Eubacteria
Archaea
Eucarya
Domain Bacteria
Prokaryotes
-> 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 Archea
__________ growing in
Yellowstone hot springs.
Thermophiles
Two Fundamentally
Different Types of Cells
Eukaryotic Cell and
Prokaryotic Cell
___________ 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
A prokaryotic cell
Eukaryotic cells are partitioned _______________
into functional compartments
Eukaryotes are distinguished by the
presence of a ___________
true nucleus
– Plasma membrane
– Genetic mechanisms
– Most organelles
Structural Similarities
– 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
Structural 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
Physiological Differences
- Synthesize proteins, carbohydrates, and lipids
- Stores molecules and materials
- Transports materials
- Detoxification of toxins
Endoplasmic Reticulum
Nickname: “Roads”
– Function: The internal
delivery system of the
cell
Endoplasmic Reticulum
- Sites of protein
synthesis - Composed of a
large and small
subunit - Types –
1. Free - move
through the
cytoplasm
2. Fixed - Attached to
endoplasmic
reticulum
Ribosomes
*Contain digestive enzymes
*Perform clean up and duties
*Digesting food or cellular invaders
*Recycling cellular components
Lysosomes
- Provide energy
for cell - Major site of ATP
synthesis - ATP- energy
coinage of the
cell
Mitochondria
*A class of diseases that causes muscle weakness and neurological
disorders are due to ______________________
malfunctioning mitochondria.
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 division
apoptosis
Motility, Flagellum
