Chapter 3 – Cell Structure And Function Flashcards
What is a cell?
Basic unit of life.
Compound light microscope
Lower magnification, Uses light beams to view images, can view live specimens.
Transmission electron microscope
2-D image, uses electrons to view internal structure, high magnification, no live specimens.
Scanning electron microscope
3-D image, uses electrons to view surface structures, high magnification, no live specimens.
Prokaryotic cells
Type of cell that lacks a membrane-bound nucleus and organelles
Eukaryotic cells
Type of cell that has a membrane-bound nucleus and membraneous organelles.
Plasma membrane
An outer membrane that regulates what enters and exits the cell.
Phospholipid bilayer
Selectively permeable, meaning it allows certain molecules - but not others - to enter the cell.
Cytoplasm
Contents of the cell between the nucleus and the plasma membrane that contains organelles
Organelles
Small membraneous structure in the cytoplasm of eukaryotic cells with a specific structure and function
Diffusion
The random movement of molecules from a higher concentration to a lower concentration.
Osmosis
The net movement of water across a semi permeable membrane.
Osmotic pressure
Controls the water movement in our bodies.
Isotonic Solutions
Have equal amounts of solute inside and outside the cell and thus do not affect the cell.
Hypotonic solutions
Have less solute then the inside of the cell and lead to lysis (bursting)
Hypertonic solutions
Have more solute then the inside of the cell and lead to crenation (shriveling)
What is facilitated transport?
A molecule is transported across the plasma membrane from the side of higher concentration to the side of lower concentration.
Active transport
The movement of molecules from a lower to higher concentration using ATP as energy; it requires an energy carrier.
Endocytosis
Transports molecules or cells into the cell via invagination of the plasma membrane to form a vesicle.
Exocytosis
Transports molecules outside the cell via the fusion of a vesicle with the plasma membrane.
Chromatin
Is the combination of DNA molecules and proteins that make up the chromosomes.
Nucleolus
Where ribosomal RNA (rRNA) is produced
Nuclear envelope
The nucleus is separated from the cytoplasm by a double membrane known as the nuclear envelope.
Ribosomes
Organelles composed of proteins and rRNA
What is the Endomembrane system?
It is a series of membranesin which molecules are transported in the cell. It consists of the nuclear envelope, endoplasmic reticulum, golgi apparatus, lysosomes, and vesicles.
Rough endoplasmic reticulum
Studded with ribosomes used to make proteins
Smooth endoplasmic reticulum
Lacks ribosomes but aids and making carbohydrates and lipids
Golgi apparatus
Flattened stacks that process, package, and deliver proteins and lipids from the ER.
Lysosomes
Membraneous vesicles made by the Golgi that contain digestive enzymes.
Vesicles
Small membraneous sacs used for transport.
What is the cytoskeleton?
A series of proteins that maintain cell shape, as well as anchors and or moves organelles in the cell.
Microtubules
Small cylindrical structure that contains 13 rows of protein tubulin. Component of the cytoskeleton; present in the cytoplasm, centrioles, cilia and flagella.
Actin filaments
Are long extremely thin fibers that usually occur in bundles or other groupings. Involved in movement.
Intermediate filaments
Are intermediate in size between microtubules and actin filaments
Extracellular matrix (ECM)
Is a meshwork of proteins and polysaccharides in close association with the cells that produce them.
Adhesion junctions
Mechanically attach adjacent cells; common in skin cells.
Tight junctions
Connections between the plasma membrane proteins of neighboring cells that produce a zipper like barrier; common and digestive system and kidney.
Gap junctions
Communication portals between cells; they channel proteins of the plasma membrane fuse, allowing easy movement between adjacent cells.
Metabolism
Includes all chemical reactions that occur in a cell.
Enzymes
Enzymes speed up the rate of a chemical reaction.
Most enzymes are proteins and enzymes are often named for the molecules that they work on called, substrates.
Active sites
Where a substrate binds
Energy of activation
The energy that must be added to cause modules to react with one another
Mitochondria
produce energy in the form of ATP
What is cellular respiration?
The breakdown of glucose to carbon dioxide and water.
Glycolysis
Means “sugar splitting”, breaks glucose into two pyruvate. Does not require oxygen.
Citric acid cycle (Krebs cycle)
A cyclical pathway that occurs in the mitochondria; releases carbon dioxide.
Electron transport chain
Series of molecules embedded in the Mito membrane. Is Aerobic
Fermentation
Is an anaerobic process, meaning that it does not require oxygen.
