chapter 6 Flashcards
Prokaryotic cell characteristics
No nucleus, DNA in an unbound region called the nucleoid, No membrane-bound organelles, Cytoplasm bound by the plasma membrane.
Eukaryotic cell characteristics
DNA in a nucleus that is bound by a membranous nuclear envelope, Membrane-bound organelles, Cytoplasm in the region between the plasma membrane and nucleus.
What structures are common to eukaryotic and prokaryotic cells?
Plasma membrane, cytosol, chromosomes, and ribosomes
Are plant and animal cells prokaryotic or eukaryotic?
eukaryotic
What are some major differences between plant and animal cells?
plant cells have a cell wall and chloroplasts, animal cells lack these characteristics, but have an extracellular matrix
nucleus
contains the DNA of the cell and is the location of RNA production
Nuclear envelope
a double membrane separating it from the cytoplasm
Role of pores in Nucleus
regulate the entry and exit of molecules from the nucleus
What is the nucleolus
located within the nucleus and is the site of ribosomal RNA (rRNA) synthesis
Ribosomes
site of protein synthesis; free ribosomes and bound ribosomes
Where are free ribosomes?
In the cytosol
Where are bound ribosomes?
On the outside of the ER or the nuclear envelope
Rough ER
studded with ribosomes, has bound ribosomes (which secrete glycoproteins), distributes transport vesicles, is a membrane factory for the cell
Smooth ER
Synthesizes lipids; Stores calcium ions; Metabolizes carbohydrates; Detoxifies drugs and poisons
Golgi apparatus
consists of flattened membranous sacs, or cisternae
Functions of the Golgi apparatus
Modifies products of the ER; Manufactures some polysaccharides; Sorts and packages materials into transport vesicles
cytoskeleton
A network of fibers extending throughout the cytoplasm; It organizes the cell’s structures and activities, anchoring many organelles
cytoskeleton: Microtubules
15-25nm (Flagella, cilia)
cytoskeleton: Microfilaments
7nm (Cell shape, cell division)
cytoskeleton: Intermediate filaments
8-12nm (Organelle anchorage)
mitochondria
site of cellular respiration (ATP synthesis); consists of two layers: Smooth outer membrane and Inner membrane folded into cristae
Inner membrane of the mitochondria
Large surface area for ATP synthesizing enzymes
Two compartments of inner membrane of mitochondria
intermembrane space and mitochondrial matrix
cell wall
extracellular structure of plant cells that protects the plant cell, maintains its shape, and prevents excessive uptake of water
What is the cell wall made of?
cellulose fibers embedded in other polysaccharides and protein
vacuoles
A cell may have one or several vacuoles, derived from endoplasmic reticulum and Golgi apparatus
Food vacuoles
formed by phagocytosis in protists
Contractile vacuoles
found in many freshwater protists, pump excess water out of cells
Central vacuoles
found in many mature plant cells, hold organic compounds and water
chloroplast
found in plants and algae, contain chlorophyll and are the sites of photosynthesis
Chloroplast structure includes three membrane layers. What are they?
Thylakoid, Inner and outer membrane, and stroma
Thylakoid
membranous sacs, stacked to form a granum
Stroma
fluid between inner membrane and thylakoid
Which cellular structures occur in both plants?
Nucleus, ribosomes, rough ER, smooth ER, Golgi apparatus, mitochondria, vacuoles, chloroplast, cell wall, cytoskeleton
Which cellular structures occur in animals?
Nucleus, ribosomes, rough ER, smooth ER, Golgi apparatus, mitochondria, vacuoles, chloroplast, cell wall, cytoskeleton, centrioles
Which cellular structures occur in prokaryotes?
prokaryotes only have ribosomes and some have a cell wall
