Chapter 1 and 2 - Foundations of Physiology & Functional Organization of the Cell (2019) - Evals #1 by Keim Flashcards
Homeostatic mechanisms are responsible for maintaining the constancy of the milieu interior. Homeostasis is currently thought of as?
The control of vital parameters
Note: Homeostasis is the control of a vital parameter. (Boron, page 4)
One of the most common themes in physiology is the negative-feedback mechanisms which is responsible for homeostasis. Negative-feedback requires at least 4 key elements below, excluding?
A single output signal most often does not operate in isolation but rather as part of a larger network of set points.
Homeostasis is currently to be argued to be not in equilibrium because
All of the above
Note: Whether at the level of the milieu intérieur or the cytoplasm of a single cell, homeostasis occurs at a price: energy. (Boron, page 4)
The hypothalamus controls the anterior pituitary, which controls the adrenal cortex, which releases cortisol, which helps control blood glucose levels. This exhibits what kind of property?
Hierarchy
Note: Finally, the physiologist must also establish hierarchy among various feedback loops. For example, the hypothalamus controls the anterior pituitary, which controls the adrenal cortex, which releases cortisol, which helps control blood glucose levels. (Boron, page 4)
The more vital a parameter is, the more systems that the body mobilizes to regulate it. If one system should fail, others are there to help maintain homeostasis. This exhibits what kind of property?
Redundancy
Note: Another theme of homeostasis is redundancy. The more vital a parameter is, the more systems the body mobilizes to regulate it. If one system should fail, others are there to help maintain homeostasis. It is probably for this reason that genetic knockouts sometimes fail to have their expected deleterious effects. (Boron, page 4)
During exercise, the system that controls body core temperature sheds heat by elaborating sweat for evaporation. However, the production of sweat ultimately reduces blood volume the system that controls blood volume will instruct the system that controls body core temperature to reduce the production of sweat. This exhibits what kind of property?
Priority
This property depends on the body’s ability to alter its response. Indeed, flexible feedback loops are at the root of many forms of physiological adaptation. For instance, at sea level, experimentally lowering the level of oxygen (the sensory stimulus) in the inspired air causes an increase in breathing (the response).
Adaptability
Determine the relative weights of feedback loops with one another
. This exhibits what kind of property?
Competition
Which of the following best describes the function of rough ER in eukaryotic cells?
Protein synthesis
It allows proteins to be synthesized and secreted continuously?
Constitutive pathway
Sorting that separates apically from basolaterally directled proteins occurs in?
Trans-Golgi Network
Protein channel that connects two cells with an unselective pore?
Gap junctions
Protection function of protein as:
Recognition particle
Membrane Fluidity: Cholesterol.
High temperature = Decreases fluidity
Sense chemical signals from external environment?
Cell membrane proteins as RECEPTORS
Membrane-bound enzymes are especially prevalent in the cells of the intestine, which participate in the final stages of nutrient digestion and absorption?
Cell membrane proteins as enzymes
Type of protein responsible for tissue defense?
Recognition protein
Functions of peripheral proteins?
A. Can form a submembranous cytoskeleton
B. Can participate in intracellular signaling
C. Adhesion molecules
D. All of the above
D. all of the above
Describes the endoplasmic reticulum, except?
Has Na-K pump
A 44-year old female was diagnosed with metastatic breast cancer. Disruption in the function of which of the following type of membrane proteins are most likely involved?
Adhesion proteins
Which of the following proteins are not embedded but are tightly attached to either cytoplasmic or extracellular surface of the plasma membrane?
Peripheral proteins
The physical properties of the bilipid layer are dependent on its chemical makeup. The nature of
the head groups of the lipid molecules would determine?
The density of the membrane
Communication function of the cell membrane is mainly due to?
Proteins
True or False:
The phospholipid bilayer is the fluid structure where phospholipid molecules can freely diffuse
within the entire leaflet which it resides.
True
Provides a transport pathway between the nucleus and cytoplasm?
Nuclear pore
Programmed cell death signal sent by?
Mitochondria
Keratin is the primary constituents of nails, hairs, and the outer layers of skin. Which filaments?
Intermediate filaments
True of tight junctions?
Impede the flow of molecules between cells
Steps in sorting to lysosomal enzymes? (Sequence)
3-1-4-2
1 Receptor-dependent transport of vesicle from Golgi to prelysosomal endosome occurs.
2 Dissociation of M6P
3 M6P binds to M6P receptor in the Golgi and enters a budding vesicle.
4 H pump acidifies the endosome
Recognition marker required to target newly synthesized hydrolytic enzymes to lysosomes?
Mannose - 6 phosphate
Apical membrane
Faces the lumen
GPI-linked characteristics?
All of the above
The cell membrane is impermeable to which of the following:
Proteins and nucleic acids
The cell membrane is primarily made up of:
Phospholipids
Which of the following affects the mobility of lipids within the bilayer aiding in the stiffening of the membrane?
Cholesterol
Destruction of the chemical bonds that link proteins to membranes may occur. Which of the following tend to be disrupted with treatment of high salt concentrations?
Ionic
Which of the following peripheral membrane protein that anchors fibrils directly to integral membrane proteins.
Ankyrin
The following are functions of integral membrane proteins, except:
No exception
Membrane proteins have several functions. Which of the following statements are true?
Integrins are adhesion molecules that attach the cells to the extracellular matrix and integral proteins can act as conductance pathway across the lipid bilayer for the passive flow of very large proteins (B & C)
The following statements refer to the complex structure of the cell membrane.
Phospholipids with long saturated fatty acids have high transition temperatures.
Which of the following statements is/are true for transmembrane movement of water soluble substances?
Alpha-helices that make up the integral proteins which allow passage of ions are amphipathic.
Communication function of the cell membrane is mainly due to?
Proteins
Which of the following statements are true of diffusion of lipids and proteins in the plane of the membrane?
Membrane fluidity is temperature dependent and transmembrane proteins are large molecules that diffusion is slower that lipids (A&B)
All communication functions are done through cell membrane proteins.
False
The phospholipid bilayer is the fluid structure where phospholipid molecules can freely diffuse within the entire leaflet which it resides.
True
Which of the following best describes the function of rough ER in eukaryotic cells?
Protein synthesis
The golgi apparatus is involved in:
all of the above
Insulin is a protein that is produced by certain pancreatic cells and secreted into the bloodstream. Which of the following choices best describes the route of your insulin from its production and exit from the cell?
Rough ER > transport vesicles > Golgi > transport vesicles > cell membrane
The following cell structure contains the powerful hydrolytic enzymes capable of digesting a wide range of materials?
lysosomes
Which of the following signals directs the protein to the lysosomes?
Attachment of your terminal mannose-6
Protein glycosylation occurs where?
Lumen of RER
Which of the following is not a characteristic of tight junctions?
Allow free-flow of cytoplasm between neighboring cells.
Unlike other intercellular junctions, it only attaches the cell to its neighbors at potential stress points.
Desmosomes
