Chapter 3 - Cell Structures Flashcards
Types of substances that can or cannot move through a cell membrane
Can: nonpolar molecules (fatty acids, vitamins ADEK, steroids), oxygen, carbon dioxide, water
Cannot: ions, polar molecules (polysaccharides, AA, glucose,nucleic acids)
Types of membrane proteins
- integral: protein physically embedded in the membrane
- transmembrane: embedded through the membrane (integral)
- : peripheral: associated with the membrane, but not embedded
The cell membrane consists of
Cholesterol, phospholipids, sphingolipids, carbohydrates, and proteins
Cell plasma membrane (plasmalemma) functions
- physical barrier: separated intracellular fluid and extracellular fluid
- gateway for exchange: regulates exchange between intracellular compartments and interstitial fluid
- communication: signals surrounding cells and senses extracellular environment
- cell structure: anchor cytoskeleton, form tissues
Endoplasmic Reticulum (def)
Flat series of membrane layers that specializes in secretion of substances (glands)
Rough and Smooth ER (def)
- rough (granular): has ribosomes on the surface for protein synthesis, molecules enter ER and are packed for secretion from the cell (neurotransmitters, hormones; beta cells of pancreas)
- smooth (agranular): no ribosomes, used for sorting of molecules, specializes in lipid synthesis, calcium storage (testes, ovaries)
Nucleus (def)
internal, organelle that contains the genetic material for cellular reproduction, consists of a nuclear envelope and nucleolus
Mitochondria (def)
The “power house” of the cell; a double-membrane organelle that produces the ATP through oxidative phosphorylation
Golgi complex (def)
Set of flat, stacked, membranous sacs that process raw material transported from the ER into finished products; sorts and directs the finished products to their final destination
Zymogens (def)
Structures that are produced in an inactive form and are made functional after being cut (insulin)
Types of cytoplasmic vesicles
- lysosomes
- peroxisomes
- transport vesicles
Lysosome def and characteristics
- contain enzymes that breakdown foreign invaders, other organelles, proteins, CHO, some fats
- serves cell for digestion and secretion
- failure to breakdown glycolipids causes Tay-Sachs
Peroxisome (def)
- breakdown fatty acids and amino acids using oxidative enzymes
- produces hydrogen peroxide
Transport vesicles (def)
Used in transport and storage of substances
Cellular inclusions (def and examples)
- nonmembrane structures within the cytoplasm
* ribosomes, proteasomes, vaults
Ribosomes (def)
Granules of RNA and proteins, translate mRNA into proteins
Proteasomes (def)
Small protein complex that destroys proteins
Vaults (def)
Small complex of RNA and proteins resembling octagonal structures, unknown exact function
The protein fibers that compose the cytoskeleton (def and types)
- assists eukaryotic cells in their overall shape, organization, transport, and movement
- microfilaments, intermediate filaments, and microtubules
Microfilaments (def)
Mechanical stiffener for microvilli, important in contractile systems (actin and myosin)
Microvilli (def)
Stiff projections on the cell surface that increase surface area and are supported by microfilaments
Intermediate filaments (def)
Structural support in cells subject to mechanical stress (myosin, keratin)
Microtubules (def and examples)
- Maintains cell shape, coordinates complex cellular movement (tubulin)
- centrioles, cilia, flagella
Specialized cell junctions
Tight junction, adhering junction, gap junction
