Compartmentalization
Internal membranes partition the eukaryotic cell into specialized regions so that different metabolic processes and enzymatic reactions occur in separate locations.
What is compartmentalization?
This ER type is studded with membrane-bound ribosomes, compartmentalizes the cell, and carries out protein synthesis.
What is the rough ER?
This double-membraned organelle is the site of aerobic cellular respiration and ATP synthesis.
What is the mitochondrion?
These non-membrane-bound structures of rRNA and protein synthesize proteins according to mRNA sequences.
What are ribosomes?
This theory says mitochondria and chloroplasts evolved from once free-living prokaryotic cells via endosymbiosis.
What is the endosymbiotic theory?
Internal membranes facilitate cellular processes in part by increasing this, giving reactions more space to occur.
What is surface area?
This ER type lacks ribosomes; it synthesizes lipids and detoxifies cells.
What is the smooth ER?
These highly convoluted folds of the inner mitochondrial membrane increase surface area for ATP production.
What are cristae?
These membrane-enclosed sacs hold hydrolytic enzymes that digest macromolecules, recycle cell parts, and execute apoptosis.
What are lysosomes?
Give two pieces of evidence for endosymbiosis found in both mitochondria and chloroplasts.
What are double membrane, circular DNA, their own ribosomes, ability to function independently? (any two)
By keeping incompatible reactions in separate locations, compartmentalization minimizes these between them.
What are competing interactions?
In the Golgi complex, transport vesicles arrive at this receiving face and modified products exit at this shipping face.
What are the cis face and the trans face?
This double-membraned organelle in plants contains chlorophyll and is the site of photosynthesis.
What is the chloroplast?
Free ribosomes make proteins for the cytosol; bound ribosomes on the RER make proteins destined for secretion, membranes, or these digestive organelles.
What are lysosomes?
Both mitochondria and chloroplasts are enclosed by this membrane feature, consistent with an engulfed prokaryote.
What is a double membrane?
Lysosomes demonstrate the value of compartmentalization: their hydrolytic enzymes stay membrane-enclosed so they cannot do this to the rest of the cell.
What is digest/break down the cell itself?
Complete the path of a secreted protein: rough ER → Golgi → transport vesicles fuse with this structure, releasing the protein by this process.
What is the plasma membrane; what is exocytosis?
Inside chloroplasts these membranous sacs stack into grana and host the light-dependent reactions.
What are thylakoids?
This large plant organelle stores water and nutrients and maintains turgor pressure.
What is the central vacuole?
Prokaryotes typically lack membrane-bound organelles, yet they can still localize functions using these.
What are internal regions with specialized structures and functions?
The inner mitochondrial membrane is highly folded into cristae. Give two ways this folding supports ATP production.
What is (1) the folds divide the mitochondrion into two internal compartments — intermembrane space and matrix — for different stages of respiration, and (2) the folds increase surface area for ATP synthesis?
Hepatitis C damages liver cells and lowers blood albumin, a secreted protein. The impaired structure is most likely this, the site of secreted-protein synthesis.
What is the rough ER?
Name the two fluid-filled compartments: the one surrounding thylakoids (site of the Calvin cycle) and the one enclosed by the inner mitochondrial membrane (site of the Krebs cycle).
What are the stroma and the mitochondrial matrix?
These organelles generate hydrogen peroxide and use catalase to split it into water and oxygen; unlike lysosomes, they are NOT part of the endomembrane system.
What are peroxisomes?
The nucleus is bounded by this double membrane with pores; within it, this dense region synthesizes rRNA for ribosomal subunits.
What is the nuclear envelope; what is the nucleolus?