Cell Functions

43 cards
Cell Functions

Biology 101 At Mt. Hood Community College
Covers The Cell Functions

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3 pts of Cell Theory
-All living organisms are composed of 1 or more cells
-Basic unit of life
-All cells arise from preexisting cells
Cell Function
-Organism growth
Cell Properties
-Separated from the surrounding environment by membrane
-Takes in raw materials & expels waste
-Absorbs energy to power cellular activities
-Builds biological molecules
Size of Cells are limited/"Surface Area to Volume Ratio"
-Metabolically active cells are small
-As surface area increases, its volume increases
-Beyond a certain volume, a cell simply would not have enough surface area to obtain nutrients & eliminate waste as needed
What is the size range of most cells?
10 um - 100 um
How small of objects can the human eye see?
Objects larger than 100um
Types of cells:
Prokaryotic & Eukaryotic
What are Prokaryotic cells?
-No Membrane bound nucleus; DNA in "nucleoid region"
-Have an outer membrane
-Have a cell wall
-Have ribosomes for protein synthesis
-Divide by mitosis
-Most are totally harmless
-Most are decomposers
-Smaller than eukaryotes
What are Eukaryotic cells?
Have a membrane bound nucleus containing DNA
What does "Pro" in Prokaryotic mean?
What does Karyotic mean?
karyotic=kernel (nucleus)
What does "Eu" in Eukaryotic mean?
What does Karyotic mean?
Eu= True
karyotic=kernel (nucleus)
Define ribosomes
Sites where the cell produces proteins according to the directions of DNA. Made of RNA & protein. Located inside nucleus of Eukaryotic cells.
What are the 3 regions of Eukaryotic cells?
Nuclear region
Cytoplasmic region
Plasma membrane region
Definition of the Nucleus:
Membrane-bound organelle containing DNA (instructions for making proteins)
What is the function of the Nuclear Envelope?
Separates nuclear material from cytoplasm
What is the function of the Nucleoplasm?
Fluid within the nuclear envelope
What is the function of the Nucleolus?
RNA & Ribosome subunit synthesis
What is the function of Chromosomes?
Contain genetic instructions (DNA) for proteins
What is the function of Nuclear Pores?
Passageways for substance exchange
Definition of Cytoplasmic Region:
Semifluid medium containing cellular organelles, molecules & ions enclosed by the plasma membrane. Separate from the nucleus.
What are Organelles?
Specialization of tasks. Process chemicals to produce useful products.
What parts are in the Endomembrane System?
ER, Golgi Apparatus, Lysosomes, Transport Vesicles
What is the function of the Endomembrane System?
Assembly, modification & transport
What are lysosomes?
-Organelles that contain digestive enzymes. They eat/break down excess or worn out organelles, food particles & engulf viruses or bacteria. It's encapsulated by the Golgi Apparatus to stop it from destroying the rest of the cell. Hydrolyze large molecules brought into the cell.
Function of the organelle of Ribosomes:
The "Workbench"
-Synthesis of amino acid sequence (proteins).
-Uses information from Nucleus (mRNA) to make proteins.
What is the Endoplasmic Reticulum?
Synthesizes & modifies proteins & lipids
What are the types of ER?
What is the rough ER?
-Studded w/ribosomes
-Function: make & modifies proteins
-Forms protein shape
-Attaches sugar
What is the smooth ER?
-Function: Make & transport lipids
-Detoxification of drugs
-Makes transport vesicles
What is the function of the Golgi Apparatus?
"Shipping Warehouses"
-Protein modification
-Protein packaging
-Protein secretion
-Lysosome formation
What is the Plant Cell Vacuole?
-Central Vacuole
-Permanent fluid filled membrane sack
-Function: Maintains Turgor Pressure. Equivalent of animal cells' lysosomes. Stores building blocks after breaking down worn out organelles.
What is the function of Mitochondria?
-They are found in both animal and plant cells
-Cell respiration! Production of ATP by transforming it from sugar
What is the function of Chloroplasts?
-Found in some prokaryotes & all plants.
-Not found in animal cells
-Photosynthesis (Transforms sunlight into chemical energy - sugar)
What is the Cytoskeleton & its function?
-Protein filaments extending from the nucleus to the plasma membrane.
-They reinforce, organize, & move internal cell parts or parts of the body
What are the types of filaments
-Actin filaments (microfilaments)
-Intermediate filaments
What is the purpose of microtubules?
-"extension poles"
-stiff and tube like. Can be assembled and disassembled easily
-Maintain cell shape
-Tracks for organelle & vesicle movement (work with motor proteins)
-Cell movement (Cilia, flagella)
-Used to move Chromosomes in cell division
What is the purpose of Actin Filaments?
-Long, thin, flexible fibers
-Pulls things
-Motion (of muscles, pseudopods, Cytoplasmic streaming)
-Membrane support
-Cell Strength
What is the purpose of Intermediate filaments?
-Maintain cell/organelle shape
Name the Cell Junctions in Animal Cells:
Name the Cell Junction in Plant Cells:
Plasmodesmata - used for communication. A series of tiny pores between plant cells which allow for the movement of materials among cells
What is Tight Junction?
-Prevents leaking.
-Joining of plasma membrane proteins creating a barrier to prevent flow between cells.
What is Adhesion Junction?
-Intercellular filaments join plasma membranes to allow stretching.
What is Gap Junction?
-Joining of two adjacent membrane channel proteins for exchange of signals & nutrients