Cell Basics Flashcards
what does it take to make a cell?
information, chemistry, compartments
What is selective permiability
In cell membranes, it is the ability to allow only certain things to enter and exit - allows for homeostasis in the cell
Cell theory
- the cell is the structural unit of life
- All organisms are composed of one or more cell types
- new cells can only arise from divison of pre existing cells
Basic properties of the cell
- highly complex and organized
- actively controlled by a genetic program
- can reproduce, make copies
- assimilate and utilize energy
- carry out chemical reactions (enzymes)
- engage in mechanical activities
- respond to stimuli
- capable of self regulation
- they evolve
Animal vs. Plant Cell
Animal cells contain lysosomes and microvilli.
Plant cells contain cell walls, vacuoles, chloroplasts and plasmodesmata
What is a cell
the structural unit of all living organisms
How do cells maintain homeostasis?
chemical reactions occur in selective permeable compartments
prokaryotes vs. eukaryotes
Prokaryotes don’t have membrane bound organelles, much smaller in size.
Eukaryotes have membrane bound organelles, much larger in size.
how do red blood cells lack
nuclei: they do not contain DNA and cannot synthesize RNA which means they cant divide and have limited repair capabilities
Oparin / Haldine hypothesis
conditions on the primitive earth favoured chemical reactions that synthesized more complex organic compounds from simpler inorganic precursers
fundamental roles of compartments
- establish physical boundaries that enable the cell to carry out different metabolic activities
- generate a micro environment to regulate biological processes
Plasma membrane
controls movement of molecules in and out of the cell and functions in cell-cell signalling and cell adhesion
Mitochondria
generate ATP by oxidation of glucose and fatty acids
Lysosomes
degrade material internalized by the cell and worn-out cellular membranes and organelles, have an acidic lumen
nuclear envelope
a double membrane that encloses the contents of the nucleus, the outer nuclear membrane us continuous with the rough ER
Nucleus
filled with chromatin composed of DNA and proteins, site of mRNA and tRNA synthesis
Nucleolous
a nuclear sub-compartment where most of the cells rRNA is synthesized
Endoplasmic reticulum
SER: contains enzymes that synthesize lipids and detoxify certain hydrophobic molecules
RER: functions in the synthesis, processing and sorting of secreted proteins, lysosomal proteins and certain membrane proteins
Golgi complex
processes and sorts secreted proteins, lysosomal proteins and membrane proteins synthesized on rough ER
vacuole
stores water, ions and nutrients, degrades macromolecules, and functions in cell elongation during growth
plasmodesmata
tubelike cell junction that span the cell wall and connect the cytoplasms of adjacent plant cells
chloroplasts
carry out photosynthesis, are surrounded by a double membrane and contain a network of internal membrane-bound sacs
cell wall
composed of cellulose, helps maintain the cells shape and provides protection against mechanical stress
microvili
increase surface area for absorption of nutrients from surrounding meium
