Chapter 3: Organelle Structure and Function Flashcards
The 3 parts of the cell theory
- All livings things are made up of one or more cells
- Cells are basic unit of structure and function
- All cells come from pre-existing cells
Why are cells so small?
They are limited by their surface area to volume ratio
Why do cells sometimes rupture?
When the surface area increases then the cell membrane accommodates volume - so if it increases in volume too fast it will rupture
Why do cells come in a variety of shapes?
They all begin as stem cells then differentiate based on function
Organelles
Internal parts of the cell that do specific jobs
Eukaryotic cells (You and Me) (true)
Have membrane bound organelles and a true nucleus
Prokaryotic cells (no)
Lack membrane bound organelles and not a true nucleus
Eukaryotic cells are found in what organisms?
Animal and plant
Prokaryotic cells are found in what organisms?
Bacteria and some unicellular organisms
Phospholipid Bilayer
A double layer of phospholipid molecules
Each molecule in the Phospholipid Bilayer has
- A polar head that is hydrophilic
- 2 non-polar tails that are hydrophobic
Function of the Cell (plasma) membrane
“Security Gate”
Controls what goes in and out of the cell
Cholestrol Molecules ( in the cell membrane)
Hard fatty molecule embedded in cell membrane
Carbhoydrates ( in the cell membrane)
Attached to the outer surface of cell membrane
Cholestrol Molecule Functions (in the cell membrane)
Gives cell membrane support and keep it water resistant
Carbohydrate (in cell membrane) function
To bind with specific molecules and aid in cell recognition
Peripheral protein (in the cell membrane)
Location
Function
Located on the interior and exterior of cell membrane
Function - self recognition and other cellular recognition
Functional names of Carbohydrate Molecules
When combined with lipid
When bound with protein
glycolipid
glycoprotein
Integral Proteins ( in the cell membrane)
Location
Function
Location - embedded in the cell membrane
Function - transport substances thru the membrane
Functional names of Integral proteins
Transmembrane proteins
Carrier proteins
Transport proteins
Channel proteins
Cytoplasm structure
Jelly - like substance between the nucleus and cell membrane
(also called cytosol when combined with organelles)
Cytoplasm function
“Atmosphere” of the cell tha contains organelles and provides a background (matrix) for cellular reactions and activities
Mitochondria structure
Looks like elongated sacs
Outer membrane acts as a barrier
Inner membrane contains folds called cristae
Cristae function
Increase surface area making more room for chemical reactions to occur and contain enzymes that speed up chemical reaations
Mitochondria function
“Gas station”
“power house”
Site of chemical reactions of cellular respiration
Cellular respiration
The process of transferring organic compounds, such ad glucose, into ATP, that cells use for energy
Nucleus contains
Nuclear envelope
Chromatin
Nucleolus
Nuclear envelope structure
Surrounds Nucleus
Has pores to allow substances to pass into/out of nucleus
Chromatin Structure
Fine strands of DNA that, when combined in pairs of two, form a Chromosome
Nucleolus structure
Dark spot in center
Nucleus function
“Boss” of the cell
Center of cell that directs all cell activities
Nuclear pore function
“Secretaries”
Allow substances into the nucleus to see the “Boss”
Chromatin function
“Brain”
Tells what proteins need to be produced
Nucleolus function
“Contractor”
Builds the ribosomes
Ribosome structure
Membrane that is made in the nucleus and then shipped out to cytosol or RER
Composed of RNA and proteins
Smallest dots within the cell
Ribosome function
“Protein Factory”
Synthesizes proteins from amino acids
2 Places ribosomes can be found
Free floating - in cytoplasm
Attached - connected to the Rough Endoplasmic Reticulum
Endoplasmic Reticulum structure
System of interconnected membranes that form tunnels throughout the cell
Endoplasmic Reticulum function
“Subway”
“Highway”
To provide a path for intracellular transport
2 types of Endoplasmic Reticulum
Smooth (SER) - no ribosomes
Rough (RER) - ribosomes attached to membrane
Smooth ER function
Makes steroids in gland cells, regulates calcium in muscle cells and breaks down toxic materials in liver cells
Rough ER function
Protein export and taking proteins to cell membrane
Golgi Apparatus structure
Consists of 6 flat stacked sacs whose membrane often connects in with the ER
Golgi Apparatus function
“Packaging Plant”
Refines, packages, and delivers proteins made by ribosomes
The 5 steps to the Golgi Apparatus packaging process
- Proteins arrive to the Golgi sacs
- Attached a sugar to the protein forming a glycoprotein
- Glycoprotein pass through each layer and are modified by either gaining or losing sugars
- Packaged into Golgi membrane and pinched off into a vesicle
- Either sent o to other organelles or sent to cell membrane to release substances as a “secretion”
Lysosome structure
Tiny sacs that contain digestive enzymes
“medium size dots”
Lysosome function
“Garbage disposals”
Get rid of waste in cell such as dead organelles and metabolic by products
Why are Lysosomes called “suicide bags”
When they burst the cell dies
Cytoskeleton structure
Long protein strands (microfilaments) Small tubes (microtubules)
Cytoskeleton function
“Bones” and “Muscles” of the cell that provide support and movement
2 types of Cytoskeleton
Microfilaments
Microtubules
Microfilaments
Made of actin protein that function in cell movement and muscle contraction
Microtubules
Hollow tubes that give support and form the spindle fibers during cell division
Cilia structure
Made of microtubules
short and numerous attached to the cell membrane
Cilia function
Assist in movement of the cell or substances across the cell
Flagella structure
Made of Microtubles
Long and tail like
only 1-3 per cell attached to the cell membrane
Flagella function
Assist in movement of the cell or substances across the cell
Peroxisome structure
Membrane sacs that contain detoxifying enzymes
Abundant in liver and kidney cells
( Bigger than Lysosomes)
Medium / large dots within the cell
Peroxisome function
Reactions that detoxify substances such as alcohol and metabolic by products such as hydrogen peroxide
2 centrioles together make
Centrosome
Centriole structure
2 hollow cylinders
Centriole function
Distribute chromosomes to newly formed cells created by mitosis (ensure proper amount of DNA goes to each new cell)
