Bio 322 midterm #1 study guide UPDATED ACTUAL
Questions and CORRECT Answers
1. Explain the historical origin of mitochondria and Both covert one form of energy into chemical energy that can be used by cell
chloroplasts Both have DNA, ribosomes, double membrane, and capable of division
Originated as prokaryotes that were engulfed by eukaryote ancestor -
endosymbiosis
2. List the cell biological differences between ▪ Eukaryotes more complex
prokaryotes and eukaryotes ▪ Eukaryotes have membrane bound organelles:
▪ Mitochondria/chloroplast, ER, Golgi, lysosome, vesicles
▪ Eukaryotes have a complex cytoskeleton
▪ Microtubules, microfilaments, interm.filaments
▪ Eukaryotes have a membrane-bound nucleus
▪ Compact, organized DNA=chromatin
3. Name three functions of cellular membranes within a (1) they keep toxic substances out of the cell; (2) they contain receptors and
cell channels that allow specific molecules, such as ions, nutrients, wastes, and
metabolic products, that mediate cellular and extracellular activities to pass
between organelles and between the cell and the outside environment; and (3)
they separate vital but incompatible metabolic processes conducted within
organelles.
4. Label a lipid bilayer in terms of specific phospholipids,
protein components and carbohydrates
5. Know the general differences between various -PHOSPHATIDYLCHOLINE IS THE MOST COMMON PHOSPHOLIPID IN CELL
phospholipids MEMBRANES.
-DIFFERENT TYPES OF MEMBRANE LIPIDS ARE ALL AMPHIPATHIC (FORM A
BILAYER IN WATER)
-SPONTANEOUSLY CLOSE IN ON THEMSELVES TO FORM SEALED
COMPARTMENTS
6. Explain why the bi-layer is self-sealing Phospholipids are made up of two parts, a hydrophilic head group and
hydrophobic tails. The hydrophilic head groups are automatically drawn to each
other because of the similar properties causing the hydrophobic tails to join
together as well. This attraction is what causes to lipid bilayer to self-seal because
it is such a strong attraction. Micelles are membranes that are made up of
phospholipids with only 1 tail. Lipid bilayers are favored over a single layered
micelle because single there is only one tail, these phospholipids can join
together more closely and make a sphere like structure that is hydrophobic all the
way through so nothing is able to pass through the membrane.
-The Lipid Bilayer Is a Flexible Two-dimensional Fluid
-The Fluidity of a Lipid Bilayer Depends on Its Composition
-Membrane Assembly Begins in the ER
-Certain Phospholipids Are Confined to One Side of the Membrane
, 9. Discuss the role of flippases and scramblases -FLIPPASES HELP TO ESTABLISH AND MAINTAIN THE ASYMMETRIC
DISTRIBUTION OF PHOSPHOLIPIDS CHARACTERISTIC OF ANIMAL CELL
MEMBRANES.
-a protein responsible for the translocation of phospholipids between the two
monolayers of a lipid bilayer of a cell membrane.
10. Be able to define the orientation and "follow" a protein -protein chaperones help them fold
(which direction it faces: extracellular space? Cytosol? -Extracellular Proteins Are Often Stabilized by Covalent Cross- Linkages
Lumen of a vesicle?) during both endocytosis(uptake)of a -endocytosis: occurs at cell surface & involves internalization of plasma
cell surface protein and exocytosis of a protein, starting membrane along with its constituent membrane proteins and lipids
with its generation in the ER - include nutrient uptake, signaling from cell-surface receptors, and many other
processes essential for cell and tissue functioning in metazoans
-exocytosis is cellular secretion: fusion between the plasma membrane and the
membrane of secretory vesicles, it is likely that proteins on these two membranes,
as well as additional proteins in cellular cytoplasm, mediate exocytosis
11. Explain the importance of bi-layer asymmetry refers to the difference between the lipid composition and/or physical properties
of the two lipid monolayers that make up a lipid bilayer.
12. Explain how a given protein would fit into the lipid have one or more segments that are embedded in the phospholipid bilayer. Most
bilayer, and what aspects of the protein and the bilayer integral proteins contain residues with hydrophobic side chains that interact with
constrict how it fits? fatty acyl groups of the membrane phospholipids, thus anchoring the protein to
the membrane.
-integral: integrated into. the membrane, have at least one hydrophobic region
that helps anchor them to the core of the phospholipid
-peripheral membrane: found outside and inside attached to either integral or
phospholipids, they do not stick into the hydrophobic core, and tend to be more
loosely attcahed
13. Explain ways in which protein mobility in the bilayer is
restricted and why that might be important
14. Discuss protein chaperons in the cytoplasm can bind to the new polypeptide to guide it into secondary and
tertiary structure
15. Contrast the potential fate(s) of a normally folded
protein, compared to a misfolded one
16. Know the reasoning behind Griffith's experiment
defining DNA as the genetic material
17. Compare and contrast hetero and euchromatin
18. Define histone, chromatin, chromosome
19. Know the two types of histones
20. Know the forces required to stabilize the DNA around
histones
Questions and CORRECT Answers
1. Explain the historical origin of mitochondria and Both covert one form of energy into chemical energy that can be used by cell
chloroplasts Both have DNA, ribosomes, double membrane, and capable of division
Originated as prokaryotes that were engulfed by eukaryote ancestor -
endosymbiosis
2. List the cell biological differences between ▪ Eukaryotes more complex
prokaryotes and eukaryotes ▪ Eukaryotes have membrane bound organelles:
▪ Mitochondria/chloroplast, ER, Golgi, lysosome, vesicles
▪ Eukaryotes have a complex cytoskeleton
▪ Microtubules, microfilaments, interm.filaments
▪ Eukaryotes have a membrane-bound nucleus
▪ Compact, organized DNA=chromatin
3. Name three functions of cellular membranes within a (1) they keep toxic substances out of the cell; (2) they contain receptors and
cell channels that allow specific molecules, such as ions, nutrients, wastes, and
metabolic products, that mediate cellular and extracellular activities to pass
between organelles and between the cell and the outside environment; and (3)
they separate vital but incompatible metabolic processes conducted within
organelles.
4. Label a lipid bilayer in terms of specific phospholipids,
protein components and carbohydrates
5. Know the general differences between various -PHOSPHATIDYLCHOLINE IS THE MOST COMMON PHOSPHOLIPID IN CELL
phospholipids MEMBRANES.
-DIFFERENT TYPES OF MEMBRANE LIPIDS ARE ALL AMPHIPATHIC (FORM A
BILAYER IN WATER)
-SPONTANEOUSLY CLOSE IN ON THEMSELVES TO FORM SEALED
COMPARTMENTS
6. Explain why the bi-layer is self-sealing Phospholipids are made up of two parts, a hydrophilic head group and
hydrophobic tails. The hydrophilic head groups are automatically drawn to each
other because of the similar properties causing the hydrophobic tails to join
together as well. This attraction is what causes to lipid bilayer to self-seal because
it is such a strong attraction. Micelles are membranes that are made up of
phospholipids with only 1 tail. Lipid bilayers are favored over a single layered
micelle because single there is only one tail, these phospholipids can join
together more closely and make a sphere like structure that is hydrophobic all the
way through so nothing is able to pass through the membrane.
-The Lipid Bilayer Is a Flexible Two-dimensional Fluid
-The Fluidity of a Lipid Bilayer Depends on Its Composition
-Membrane Assembly Begins in the ER
-Certain Phospholipids Are Confined to One Side of the Membrane
, 9. Discuss the role of flippases and scramblases -FLIPPASES HELP TO ESTABLISH AND MAINTAIN THE ASYMMETRIC
DISTRIBUTION OF PHOSPHOLIPIDS CHARACTERISTIC OF ANIMAL CELL
MEMBRANES.
-a protein responsible for the translocation of phospholipids between the two
monolayers of a lipid bilayer of a cell membrane.
10. Be able to define the orientation and "follow" a protein -protein chaperones help them fold
(which direction it faces: extracellular space? Cytosol? -Extracellular Proteins Are Often Stabilized by Covalent Cross- Linkages
Lumen of a vesicle?) during both endocytosis(uptake)of a -endocytosis: occurs at cell surface & involves internalization of plasma
cell surface protein and exocytosis of a protein, starting membrane along with its constituent membrane proteins and lipids
with its generation in the ER - include nutrient uptake, signaling from cell-surface receptors, and many other
processes essential for cell and tissue functioning in metazoans
-exocytosis is cellular secretion: fusion between the plasma membrane and the
membrane of secretory vesicles, it is likely that proteins on these two membranes,
as well as additional proteins in cellular cytoplasm, mediate exocytosis
11. Explain the importance of bi-layer asymmetry refers to the difference between the lipid composition and/or physical properties
of the two lipid monolayers that make up a lipid bilayer.
12. Explain how a given protein would fit into the lipid have one or more segments that are embedded in the phospholipid bilayer. Most
bilayer, and what aspects of the protein and the bilayer integral proteins contain residues with hydrophobic side chains that interact with
constrict how it fits? fatty acyl groups of the membrane phospholipids, thus anchoring the protein to
the membrane.
-integral: integrated into. the membrane, have at least one hydrophobic region
that helps anchor them to the core of the phospholipid
-peripheral membrane: found outside and inside attached to either integral or
phospholipids, they do not stick into the hydrophobic core, and tend to be more
loosely attcahed
13. Explain ways in which protein mobility in the bilayer is
restricted and why that might be important
14. Discuss protein chaperons in the cytoplasm can bind to the new polypeptide to guide it into secondary and
tertiary structure
15. Contrast the potential fate(s) of a normally folded
protein, compared to a misfolded one
16. Know the reasoning behind Griffith's experiment
defining DNA as the genetic material
17. Compare and contrast hetero and euchromatin
18. Define histone, chromatin, chromosome
19. Know the two types of histones
20. Know the forces required to stabilize the DNA around
histones
