Chapter 7 Objectives Flashcards
What makes up the prokaryotic cell structure?
- Plasma Membrane
- Chromosome nucleoid
3.Plasmids (Small DNA molecules) - Ribosomes (RNA molecules & proteins)
- Flagella (tail!)
- Cytoskeleton - long fibrous structure
cell wall (glyco-lipids)
What are key differences between prokaryotic and eukaryotic cells?
Eukaryotic are 10x larger than prokayotic cells
Eukaryotic have compartmentalization with membrane bound organelles like the nucleous, ER, and mitochondria.
What is the nucleoid?
It is the “center” of the prokaryotic cell that hold 1 single chromosome made up of 1 large DNA molecule and small number of proteins. It is highly compact, supercoiled helix - but has no membrane that eukaryotic cells have around their nucleus.
What is cyotplasm? cytosol?
Cytoplasm is all of the contents of a cell, excluding the nucleus, bounded by the plasma membrane.
They cytosol is the fluid portion of they cytoplasm.
Ribosome
Components: Complex of RNA and proteins
Function: Protein synthesis
*no membrane
Plasma membrane
Components: Phospholipid bilayer with transport and receptor proteins
function: selective permeability, maintains intracellular environment
* single membrane
Nucleus
Components: Chromosomes, Nucleolus, Nuclear lamina
Function: Genetic information, assembly of ribosome subunits, structural support
*Double membrane (nuclear envelope with nuclear pores)
Nucleolus
Components: ribosomal subunits
Function: RNA molecules that make up ribosomes are manufactured & assembled
*inside the nucleus - no membrane of its own
Nuclear Pores
An opening in the nuclear envelope that connects the inside of the nucleus with the cytoplasm and through which molecules such as mRNA and some proteins can pass
Nuclear Lamina
a lattice like sheet of fibrous nuclear lamins, which are one type of intermediate filaments. Lines the inner membrane of the nuclear envelop, stiffening the envelope and helping organize the chromosomes
endomembrane system
A system of organelles in eukaryotic cells that performs most protein and lipid synthesis. Includes the ER, Golgi apparatus, and lysosomes
Rough Endoplasmic Reticulum (RER)
Components: Branching sac network with attached ribosomes
Function: Protein synthesis and processing
*Single membrane with receptors for entry of selected proteins
Golgi Apparatus
Components: stack of flattened cisternae
Function: Protein processing & packaging
*Single membrane and contains receptors for products of the RER
Smooth Endoplasmic Reticulum
Components: Network of branching sacs and Enzymes for synthesizing lipids
Function: LIPID synthesis
*Single membrane with enzymes for synthesizing phospholipids
Lysosomes
Components: Acid hydrolases (catalyze hydrolosis reactions)
Function: digestion and recycling
*single membrane with proton pumps
Peroxisomes
Components: Enzymes that catalyze oxidation reactions and Catalase (processes peroxide)
Function: Oxidation of fatty acids, ethanol, or other compounds
*single membrane
Vacuoles
Components: varies - pigments, oils, carbs, water, or toxins
function: varies - coloration, storage of any above
* Single membrane & transporters for selected molecules
Mitochondria
Components: Enzymes that catalyze oxidation-reduction reactions, ATP synthesis
Function: ATP production & respiration
*DOUBLE membrane!; inner membrane contains ATP enzymes
Chloroplasts
Components: pigments & enzymes that catalyze oxidation-reduction reactions
Function: Production of ATP and sugars via photosynthesis
*DOUBLE membrane and membrane-bound sacs in interior!!!
Cytoskeleton
Components: Actin filaments, intermediate filaments and microtubules
Function: Structure; movement of materials;sometimes movement of whole cell in some species
*NO membrane
Cell wall
Components: Carbohydrate fibers running through carb or protein matrix
Function: protection and support
*no membrane
glycosylation
the addition of a carbohydrate group to a molecule
glycoprotein
any protein with one or more covalently bonded carbohydrate
proteoglycan
?
phagocytosis
uptake by a cell of small particles or cells by pinching off the plasma membrane to form small membrane-bound vesicles; one type of endocytosis
protease
an enzyme that can degrade proteins by cleaving to the peptide bonds between amino acid residue
mitochondrial matrix
central compartment of a mitochondrion, which is lined by the inner membrane; contains enzymes and substrates of the citric acid cycle and mitochondrial DNA
microtubules
structure: hollow tube
subunits:alpha and beta tubulin dimers
functions: maintain cell shape by resisting compression
moves cells via flagella or cilia
move chromosomes during cell division
assist formation of cell plate during plant cell division
move organelles
provide tracks for intracellular transport
microfilaments/actin filaments
subunits: cytoskeletal element with the smallest diameter
fibrous structures made of globular protein actin
structure: asymmetrical subunit with distinct polarity that grows and shrinks as actin subunits are added or subtracted to each end of the structure. Tend to grow at the plus end because polymerization happens faster there.
double helix strands
function: movement!
maintain cell shape by resisting tension
move cells via muscle contraction or cell crawling
divide animal cells in two
move organelles and cytoplasm in plants, fungi, and animals
intermediate filaments
structure: fiber wound into thick cables
subunits: keratin or vimetin or lamin or other proteins
function: maintain cell shape by resisting tension
anchor nucleus and some other organelles
motor proteins
TBD
flagella
TBD
cillia
TBD
cristae
TBD
centrosomes
TBD
centrioles
TBD
cytoplasmic streaming
TBD
thylakoids
TBD
extracellular matrix (ecm)
TBD
