Describe the similarities and differences between prokaryotic and eukaryotic cells
Prokaryotic: unicellular, dna in nucleoid (no nucleus), circular dna, no membrane-bound organelles, smaller; bacteria
Eukaryotic: multicellular or unicellular, nucleus, linear dna, membrane-bound organelles, larger; plants, animals, fungi, protist
Both: have dna, ribosomes, plasma membrane, filled with cytosol
Structure: Enclosed by nuclear envelope (double-membrane) and contains a nucleolus (small dense area of DNA, non-dividing cells only)
Function: stores genetic info (DNA) of a eukaryotic cell
Ribosomes
Structure: complexes of ribosomal RNA (rRNA) and protein; a large and small unit
Function: protein synthesis
Rough ER
Structure: network of membranous tubes with ribosomes attached to the outside
Function: production of membrane or secretory proteins, creates plasma membrane sections
Smooth ER
Structure: network of membranous tubes without ribosomes
Function: synthesizes lipids, detoxifies drugs/poisons (liver cells), stores calcium ions
Golgi Apparatus
Structure: Membranous flat stacks called cisternae (singular: cistern); cis face --> faces rough ER (receive), trans face --> faces plasma membrane (send)
Function: receives vesicles from the rER containing proteins to modify, store, and ship (in plants: synthesizes polysaccharides)
Lysosomes
Structure: a membranous sac that contains hydrolytic enzymes
Function: digest (hydrolyze) macromolecules and recycling them
Vacuole
Structure: a membrane-bound sac
Function: storage of cell material
Mitochondria
Structure: double-membrane (phospholipid bilayer) organelle, with highly folded inside (cristae); Intermembrane space --> between the inner and outer membrane, Matrix --> cytosol-like filling holding enzymes, ribosomes, and dna
Function: performing cellular respiration -->breaking down C6H12O6 to produce ATP (cellular energy)
In both plant and animal cells
Chloroplast
Structure: double-membrane organelle, with flat disks (thylakoids) that contain photosynthetic pigments; Intermembrane Space (b/t double membrane), Stroma --> cytosol-like filling holding enzymes, ribosomes, and dna
Function: Performing photosynthesis (using light, CO2, and H2O to produce C6H12O6 which will be used for cellular respiration) and O2
Just plant cells
Peroxisome
Structure: A small membranous sac
Function: Contains enzymes that remove H from molecules and create H2O2 (peroxide) [biproduct]
Breaks down fatty acids --> making their products useable for cellular respiration
Cytoskeleton
Structure: extensive network of microtubules, intermediate filaments, & microfilaments
Function: Mechanical support and structure to the inside of a cell, cell movement
Plasma Membrane
Structure: phospholipid bilayer, mainly created by vesicles
Function: separate either the inside/outside of a cell or an organelle
Cell Wall
Structure: External to the plasma membrane, made mostly of carbs & proteins
- Bacteria -->Peptidoglycans (polysac. and polypep.)
- Plant --> Cellulose
- Fungal --> Chitin + some protein
Function: protection & support
Extracellular Matrix (ECM)
Structure: a mesh-like network of various molecules
Function: Links cells together to form tissue, plays role in cell communication
Animal Cell:
- no chloroplasts, just mitochondria
- (not shown) small vacuoles
- centrioles
- lysosomes
Identify the parts of an animal and plant cell (use study guide or google label less cell diagrams)
(use study guide or google label less cell diagrams)
Describe the process of protein secretion involving the organelles of the endomembrane system in detail
1. The ribosomes on the rough ER synthesize a protein that travels through the lumen (inner tubes) of the rER
2. The protein leaves the rER in a membranous vesicle and travels to the cis face of the Golgi apparatus to be modified
3. As the protein travels through the cisternae of the Golgi, enzymes modify the protein until the protein reaches the trans face of the Golgi and buds off through a membranous vesicle toward the plasma membrane
4. The vesicle merges with the plasma membrane and as the vesicle merges the protein is secreted from the cell and either leaves the cell completely or binds onto the surface of the plasma membrane
What are the 3 possible locations for products of the rough ER? describe
Secretion --> To the Plasma Membrane through the process of protein secretion
Stored --> Vacuoles
Used --> Lysosomes to be broken down, recycled, or the enzymes of the lysosome (further explained through how lysosomes work)
What are the 3 different kinds of vacuoles?
- Food Vacuole --> storage of food to be digested by lysosomes later
- Central Vacuole --> storage of water and nutrients for a plant cell
- Contractile Vacuole --> pumps excess water out of a cell (freshwater protist only)
What are the structural and functional similarities and differences between mitochondria and chloroplasts?
Both:
- double-membrane
-ribosomes
-circular DNA
-Used for energy production
-Intermembrane Space
Mitochondria:
-Cellular respiration (glucose to ATP)
-Matrix
-Cristae
Chloroplast:
-Photosynthesis (CO2 and H2O into glucose and O2)
-Stroma
-Thylakoids
Describe the Endosymbiotic Theory in detail
1. A prehistoric cell's membrane started to fold within itself encapsulating its DNA into a nucleus and forming the ER becoming a primitive eukaryotic cell
2. That primitive eukaryotic cell engulfed a smaller prokaryotic cell with the capabilities of producing ATP using glucose, that prokaryotic cell would be wrapped by the membrane of the primitive eukaryotic cell and become the mitochondria and the eukaryotic cell would be classified as an early animal cell
3. The early animal cell would engulf another small prokaryotic cell with the capability to produce glucose for energy using light, that prokaryote would get wrapped by the membrane of the eukaryote and would become the chloroplast and the eukaryotic cell would be classified as a early plant cell
What evidence supports the endosymbiotic theory?
1. Circular DNA
-> Mitochondria and Chloroplast both have circular DNA which is only found in prokaryotic cells supporting the idea that these organelles were once prokaryotes
2. Double Membrane
-> Mitochondria and Chloroplast have an inner membrane that resembles the membrane of a prokaryote and the outer membrane that resembles one of a eukaryote. Supports the idea that when the organelles were prokaryotes, after getting engulfed they were surrounded by the membrane of the primitive eukaryote
3. Autonomous/Grow and Divide independently
-> Mitochondria and Chloroplast have the capabilities to function on their own without the guidance of the nucleus of the eukaryotic cell they inhabit. Supports the theory that they were once independent and free-living
Describe the similarities and differences between the 3 components of the cytoskeleton
1. Microtubules
- Largest component
- Hollow rod of proteins
- Building and degrading
- "Roads" for organelles
- Centrioles, Flagella, Cilia
2. Intermediate Filaments
-Medium component
- Protein fibers supercoiled into thick cables
- permanent framework inside the cell
3. Microfilaments
- Smallest component
- Two intertwining strands of proteins
- Build and degrade
- Cell mobility
Similarities:
-made of proteins
- Microtubules and Microfilaments build, degrade, and assist in movement
Similarities and difference between flagella and cilia
Flagella:
- Large, long tail-like appendage
Cilia:
-Short, brush-like appendage
Both:
-Used for movement
Describe the structure of the plasma membrane and cell wall
Plasma Membrane:
- A phospholipid bilayer that is flexible and acts as a barrier between the inside and outside of a cell
Cell Wall:
-Rigid and structured that exists on the outside of the plasma membrane for protection and support and differs in compound depending on the type of cell
(bacterial [peptidoglycan] , plant [cellulose] , or fungal [Chitin + some protein])
What's the purpose of the ECM
ECM = Extracellular Matrix
Facilitates cell-to-cell contact to form tissue and cell communication
Difference between types of cell-cell junctions in plants and animals
Plants: Plasmodesmata --> an open channel in the cell wall of neighboring plant cells
Animals:
(Top) Tight Junction --> attach neighboring animal cells with interwoven rows of proteins
(Middle) Desmosomes --> Connect cells together in strong sheets w/ intermediate filaments
(Bottom) Gap Junction --> pores b/t neighboring animal cells that allow material to pass through