Cell Structure & Function
What do all cells have?
Plasma Membrane, Cytoplasm, Chromosomes, and Ribosomes
Ribosome structure & function
-NOT membrane-enclosed
-consist in 2 parts (large & small subunits)
-composed of rRNA & proteins
-synthesize proteins according to mRNA sequence
Golgi complex structure & function
-series of flattened membrane sacs
-modifies and sorts materials from ER, Adds molecular tags
-Packages materials into new transport vesicles that exit the membrane via EXOCYTOSIS.
What two locations can ribosomes be found?
Cytosol and Bound to the ER (Rough)
What are three differences between Prokaryotes and Eukaryotes?
Prokaryotes: DNA in NUCLEOID REGION, Smaller in Size, No membrane bound organelles.
Eukaryotes: DNA in NUCLEUS, larger and more complex, contain membrane bound organelles.
Smooth ER structure & function
-network of membrane tubes
-NO ribosomes
-cell detoxification & lipid synthesis
Lysosomes structure & function
-Membrane-enclosed sacs found in some eukaryotic cells that contain hydrolytic enzymes
-Hydrolytic enzymes can be used to digest a variety of materials such as damaged cell parts or macromolecules
-Lysosomes can recycle their own cell's organic materials: AUTOPHAGY
The Golgi Complex contains flattened membranous sacs called?
Cisternae
-has directionality, Cis Face and Trans Face
Type of organelle which are membraneous sacs with hydrolytic enzymes that catalyze reactions that produce H2O2.
Peroxisomes
Rough ER structure & function
-network of membrane tubes
-has ribosomes attached
-packaging newly synthesized proteins for export
Vacuole structure & function
-Membrane-bound sacs in eukaryotic cells
-Play a variety of roles ranging from water & macromolecule storage to the release of waste from the cell
-Form via PHAGOCYTOSIS (Cell Eating)
What is some key evidence that explains the endosymbiont theory or the theory that explains the similarities that mitochondria and chloroplasts have to a prokaryote.
Evidence:
-They are both double membrane
-Both contain their own CIRCULAR DNA
-Both are capable of functioning on their own (reactions such as transcription and translation)
-Both can self-replicate
Animal vs. Plant Cells
-Animal: no chloroplasts, no cell wall, shrivel when hypertonic, Centrosomes, Flagella
-Plant: larger vacuoles, more square in shape due to cell wall, large central vacuole, plasmodesmata
Describe mitochondrial structure & function
-double membrane
-Outer membrane is smooth and inner membrane has folds called cristae (divides mitochondria into two internal COMPARTMENTS).
-site of electron transport & ATP synthesis (cellular respiration)
What are the 3 types of fibers in the cytoskeleton and main function of each?
-Microtubules: hollow rod-like structures made of the protein tubulin that serve as structural support, cell motility, and assist in the SEPARATION OF CHROMOSOMES
-Microfilaments: thin solid rods made of the protein actin that maintain cell shape and assist in MUSCLE contraction and cell motility.
-Intermediate Filaments: fibrous proteins made up of varying subunits that serve to maintain cell shape and ANCHOR nucleus and organelles.
What is Autophagy?
-cell eating
-lysosomes
-allows a cell to renew itself by "eating" dead or damaged cells
What is the Calvin Cycle and in what organelle does it occur in the cell?
The Calvin Cycle or the Light Independent Reaction of Photosynthesis uses carbon dioxide to produce organic molecules (glucose). The calvin cycle occurs in the Stroma (fluid in the chloroplast).
Describe the structure & function of chloroplasts
-double membrane
-thylakoids(light dependent reactions), stroma(light independent reactions), granum(Stacks of thylakoids).
-only in plant cells
Why is compartmentalization important in eukaryotic cells?
-minimizes competing reactions (prevents reactions from occuring in the same location.
-increases surface area
-overall increase in efficiency
What is the function of the nucleolus?
Dense region of the nucleus where ribosomal RNA (rRNA) is synthesized. rRNA is combined with proteins to form large and small subunits of ribosomes.