Ultrastructure of Cells 1.2 Flashcards
Essential Idea (Ultrastructure of Cells 1.2)
Eukaryotes have more complex structure than prokaryotes
Three Domains
- Bacteria (prokaryotic)
- Archaea (prokaryotic)
- Eukaryota (eukaryotes)
Prokaryotes
- Unicellular organisms with no internal compartmentalization, no nucleus and no membrane-bound organelles
- Metabolic processes occur within the cytoplasm
- Belong to different domains (bacteria and archaea) due to differences in the cell wall composition and RNA
- 1 micro meter in size
Prokaryotes Cell Structure (9)
- Cell wall
- Plasma Membrane
- Capsule (only in some)
- Cytoplasm
- Pili
- Flagella
- 70S ribosomes
- Nucleoid Region
- Plasmids
70S vs 80S Ribosomes
- Ribosomes in prokaryotic cells 70S, are smaller, lighter and less dense than ribosomes in eukaryotic cells 80S
- Both composted of two subunits (50S & 30S = 70S, 60S & 40S = 80S)
E-coli Microscope Organelles Image
- Nucleoid region is lighter in the middle on in the microscope image
- Ribosomes are dark spots
Binary Fission
- Asexual reproduction process
- Nucleoid DNA (chromosomes) are replicated
- Two copied of DNA molecules move to opposite ends and the cell elongates (grows)
- Plasma membrane grows inward and pinches off to form two separate identical cells (process called cytokinesis)
Eukaryotes
- Genetic material is isolated from the cytoplasm by the nucleus
- Eukaryota domain has four kingdoms: protocista, fungi, plantae (plant) and animalia (animal)
- Vary in size (yeast to blue whale)
- Compartmentalized
Compartmentalization
- Refers to the formation of compartments within the cell by membrane bound organelles
- Allows for greater metabolism efficiency
- pH can vary to optimal conditions for different enzymes
- Toxic or damaging substances are isolated
- Flexible in changing position and quantity of organelles based on cell requirements
Eukaryote Cell Structure (11)
- Plasma membrane
- Cytoplasm
- Mitochondria
- 80S ribosomes
- Nucleus
- Nucleolus
- Smooth endoplasmic reticulum
- Rough endoplasmic reticulum
- Golgi Apparatus
- Vesicles
- Flagella or cilia
Animal Cell Structure
- Small Vacuole
- Lysosomes
- Centrioles
- Animal cells store carbohydrates as glycogen and are not a fixed shape
Plant Cell Structure
- Large vacuole
- Cell Wall
- Chloroplast
- Plant cells store carbohydrates as starch and are a fixed shape
Types of Pancreas Gland Cell
Endocrine and exocrine
Endocrine Pancreas Gland Cell
Secrete hormones into the blood stream
Exocrine Pancreas Gland Cell
Secrete digestive enzymes into a duct that goes to the small intestine to digest food and has large quantities of ribosomes and rough ER
Palisade Mesophyll Cell
The leafs function is photosynthesis, taking CO2, water and light to make oxygen and energy
Microscope Resolution
- The shortest distance between two separate points in field of view that can still distinguish as distinct objects
- Electron has higher resolution than light
- Degree of detail within an image
Plasma Membrane Function
Controls movement of substances in and out of the cell
Cytoplasm Function
Fills the cell and holds all organelles, contains enzymes that catalyze reactions, site of cellular reactions
Mitochondria Function
Site of cellular respiration in which ATP is generated, has different DNA
ATP
Adenosine triphosphate, an organic compound used for energy
Ribosomes Function
Sites of protein synthesis
Nucleus Function
Controls all activity in the cell, composed of two membrane nuclear envelops containing pores, and pores bring RNA in and out
Nucleolus Function
Part of the nucleus involved in ribosome prodution
Smooth Endoplasmic Reticulum Function
Produced and stores lipids
Lipids
Fatty, waxy or oily compounds
Rough Endoplasmic Reticulum Function
Transports proteins produced by ribosomes to the golgi apparatus, and is a flattened membrane system covered in ribosomes
Golgi Apparatus Function
Processes and packages proteins, normally released in golgi vesicles
Vesicles Function
Small sac that transports and releases substances, exocytosis
Flagella / Cilia Function
Microtubules that are involved in cell locomotive
Small Vacuole Function (animal cell)
Used for temporary material storage or to transport substances
Large Vacuole Function (plant cell)
helps osmotic balance and storage of substances (salts, minerals, nutrients and proteins to help the plant grow)
Lysosomes Function (animal cell)
contain hydrolytic (digestive) enzymes and important for the destruction of microbes, digests worn out organelles
Centrioles Function (animal cell)
Important in nuclear division process, establishes microtubules, paired cylinders
Chloroplast Function (plant cell)
Responsible for photosynthesis, has different DNA
Cell Wall Function
Prevents cell from bursting in hypotonic media and helps maintain cell shape, has rigid extracellular structure made from protein sugars
Capsule Function
Only in some prokaryotic cells, protects the cell from being ingested or destroyed and is made of polysaccharides (sugar chains)
Pili Function
Protein filaments on the cell wall that help adhesion and exchange of plasmids between two cells
Plasmid Function
Small circles of DNA that carry a few genes, which give the cell antibiotic resistance
Nucleoid Region Function
Controls all the activities of the cell and is circular naked DNA
