What is a major difference between prokaryotic and eukaryotic cells?
the location of chromosomes
Where are the chromosomes located in eukaryotic cells?
contained in a membrane-enclosed organelle, the nucleus
Where are the chromosomes located in prokaryotic cells?
the DNA is concentrated in the nucleoid without a membrane separating it from the rest of the cell
Where is cytoplasm located in Eukaryotic cells? In prokaryotic cells?
(EUK) - The region between the nucleus and the plasma membrane; (PRO) - all material within the plasma membrane of a prokaryotic cell
What cells have membrane-bound organelles? Which don't?
Eukaryotic cells have a variety of membrane-bound organelles; Prokaryotes lack these
Which type of cell is larger?
Eukaryotic cells are larger
What is a chromatin?
chromosomes are made up of these; they are a complex of proteins and DNA
how many chromosomes does a typical human cell have? how many does a human sex cell have?
Where is RNA synthesized and assembled with proteins?
in the nucleolus
What is the function of ribosomes?
building a cell's proteins, they are the organelles that carry out protein synthesis
Where are free ribosomes?
suspended in the cytosol and synthesize proteins that function with the cytosol
Where are bound ribosomes?
attached to the outside of the ER or nuclear envelope.
What does the endomembrane system regulate?
protein traffic and performs metabolic functions in the cell
What is part of the endomembrane system?
nuclear envelope, ER, Golgi apparatus, lysosomes, vacuoles, and the plasma membrane
What does the ER do?
manufactures membranes and performs many other biosynthetic functions
What do the enzymes of the smooth ER do?
synthesize lipids, including oils, phosholipids, and steroids; enzymes help detoxify poisons and drugs (alcohol and barbituarates)
What does the smooth ER store?
What are the uses of calcium in the muscle cell?
muscle cells have a specialized smooth ER that pumps calcium ions from the cytosol and stores them in its cisternal space; when a nerve impulse stimulates a muscle cell, calcium ions rush from the ER into the cytosol, triggering contraction
What is the smooth ER abundant in?
What is abundant in the rough ER?
cells that secrete proteins
What does the rough ER synthesize?
membrane-bound proteins are synthesized directly into the membrane; enzymes in the rough ER also synthesize phospholipids from precursors in the cytosol
What does the Golgi apparatus do?
shipping and receiving center for cell products
What are cisternae?
makes up the Golgi apparatus and they are flattened membranous sacs
what are lysosomes?
digestive compartments; a membrane-bound sac of hydrolytic enzymes that an animal cell uses to digest macromolecules
What is phagocytosis?
amoebas eat by engulfing smaller organisms; the food vacuole formed by phagocytosis fuses with a lysosome, whose enzymes digest the food
what happens during autophagy?
a damaged organlle or region of cytosol becomes surrounded by membrane; the cell is renewed
What is apoptosis
programmed cell death
What are food vacuoles?
food vacuoles are formed by phagocytosis and fuse with lysosomes
what are contractile vacuoles?
pump excess water out of the cell to maintain the appropriate concentration of salts
what are the functions of the central vacuole?
stockpiling proteins or inorganic ions, disposing of metabolic byproducts, holding pigments, and storing defensive compounds that defend the plant against herbivores
What are mitochondria the sites of?
sites of cellular respiration, generating ATP from the catabolism of sugars, fats, and other fuels
What do peroxisomes do?
generate and degrade H2O2 (hydrogen peroxide) to water; some break fatty acids down to smaller molecules that are transported to mitochondria
What does the cytoskeleton do?
provides support, motility, and regulation
What are the three main types of fibers that make up the cytoskeleton?
microtubules, microfilaments, and intermediate filaments