PHYSIO SCI221 FINAL EXAM QUESTIONS AND
ANSWERS LATEST UPDATE
Positive and Negative Feedback Difference
Positive- rare in the body, result of sudden occurrence (or amplifies a change from
normal point)
Example would be:
-birth
-blood clotting
-Increases the original stimilus
-milk production until baby is done feeding
-uterine contractions during birth
-fever (virus/bacteria, body heats self to get rid until enemy is destroyed)
Negative-Most homeostatic mechanisms are negative- effect is to shut off or reduce
original stimulus-
Example would be:
-heart rate
-blood pressure
-blood gluclose
-body temp
-oxygen levels in the blood
-thirst sensensation
feedback mechanism that detect change in environment
receptor
The receptor senses environmental stimuli, sending the information to the integrating
center.
Homeostasis
The ability of a system or living organism to adjust its internal environment to maintain a
stable equilibrium, such as the ability of warm-blooded animals to maintain a constant
body temperature.
What is the CONTROL CENTER for Homeostasis
Determines the level for a variable, analyzes info, determines appropriate response-
send along efferent pathway to the effector
Homeostatic control mechanisms have at least three interdependent components: a
receptor, integrating center, and effector.
What is thermoregulation
--body process that balances heat production and heat loss
maintain body's regular temperature- 37 degrees C 98.6 degrees F
-Internal thermoregulation contributes to animal's ability to maintain homeostasis within
a certain range of temperatures. As internal body temperature rises, physiological
processes are affected, such as enzyme activity.
,What is the process for thermoregulation
-in response to varying body temperatures, processes such as enzyme production can
be modified to acclimate to changes in the temperature.
-Endotherms regulate their own internal body temperature, regardless of fluctuating
external temperatures, while ectotherms rely on the external environment to regulate
their internal body temperature.
-Homeotherms maintain their body temperature within a narrow range, while
poikilotherms can tolerate a wide variation in internal body temperature, usually
because of environmental variation.
-Heat can be exchanged between environment and animals via radiation, evaporation,
convection, or conduction processes.
Definition of ischemia
deficient supply of blood to a body part (such as the heart or brain) that is due to
obstruction of the inflow of arterial blood.
function of lysosomes
-digest/break down food, waste, and broken parts
- A lysosome is an organelle containing digestive enzymes which it uses to function as
the digestion and waste removal for cells, food particles, bacteria, etc.
function of peroxisomes
-oxidation of toxic molecules
-oxidating fatty acids and amino acids into H202 peroxide, which is then broken down
into h20 and 02 by the enzyme catalase
function of ribosomes
-protein synthesis
-Ribosomes are a cell structure that makes protein. Protein is needed for many cell
functions such as repairing damage or directing chemical processes. -Ribosomes can
be found floating within the cytoplasm or attached to the endoplasmic reticulum.
function of mitochondria
-Cellular respiration, makes ATP.
-The most prominent roles of mitochondria are to produce the energy currency of the
cell, ATP (i.e., phosphorylation of ADP), through respiration, and to regulate cellular
metabolism. The central set of reactions involved in ATP production are collectively
known as the citric acid cycle, or the Krebs cycle.
function of golgi apparatus
-Modify, sorts and packages proteins and other materials from the ER for starage in the
cell or secretion outside the cell
-It is also involved in the transport of lipids around the cell, and the creation of
lysosomes. The sacs or folds of the Golgi apparatus are called cisternae.
The process of DNA to RNA
-transcription
-Transcription takes place in two broad steps. ... The pre-messenger RNA is then
"edited" to produce the desired mRNA molecule in a process called RNA splicing.
What role does DNA and RNA play in protein initiation
Ribosomal RNA (rRNA) associates with a set of proteins to form ribosomes. These
complex structures, which physically move along an mRNA molecule, catalyze the
, assembly of amino acids into protein chains. They also bind tRNAs and various
accessory molecules necessary for protein synthesis.
Difference between protein primary, secondary, and tertiary structures in
structure and function
-Primary structure is the order in which what amino acid is bound the other with a
peptide bond. This is coded for by the order of codons in a gene.
-Secondary structure is how the chains on amino acids interact with each other to form
beta barrels and alpha helixes. This structure is determined by hydrogen bonds
between the different amino acids.
-Tertiary structure is when the secondary structures interact with each other through
disulphide bonds, hydrogen bonds, hydrophobic/hydrophilic interactions etc. This is all
determined by the placement of certain amino acids within the proteins secondary
structure.
functions of microtubules, tubulin, microfilaments, and intermediate filaments
- Microtubules are hollow, fibrous shafts whose main function is to help support and give
shape to the cell. They also serve a transportation function, as they are the routes upon
which organelles move through the cell.
-Microtubules function in many essential cellular processes, including mitosis. Tubulin-
binding drugs kill cancerous cells by inhibiting microtubule dynamics, which are required
for DNA segregation and therefore cell division.
-functions are primarily mechanical and, as a class, intermediate filaments are less
dynamic than actin filaments or microtubules. Intermediate filaments commonly work in
tandem with microtubules, providing strength and support for the fragile tubulin
structures.
Difference between metaphase, Prophase, interphase, and G phase
-Metaphase-the second stage of cell division, between prophase and anaphase, during
which the chromosomes become attached to the spindle fibers.
-Prophase the first stage of cell division, before metaphase, during which the
chromosomes become visible as paired chromatids and the nuclear envelope
disappears. The first prophase of meiosis includes the reduction division.
-Interphase the resting phase between successive mitotic divisions of a cell, or between
the first and second divisions of meiosis.
-G phase- is the first of four phases of the cell cycle that takes place in eukaryotic cell
division. In this part of interphase, the cell synthesizes mRNA and proteins in
preparation for subsequent steps leading to mitosis. G1 phase ends when the cell
moves into the S phase of interphase.
Difference between Desmosomes, tight junctions, and Gap junctions
-Desmosomes- a structure by which two adjacent cells are attached, formed from
protein plaques in the cell membranes linked by filaments.
-Tight junctions- a specialized connection of two adjacent animal cell membranes such
that the space usually lying between them is absent.
-Gap Junctions-Gap junctions allow the exchange of ions, second messengers, and
small metabolites between adjacent cells and are formed by two unrelated protein
ANSWERS LATEST UPDATE
Positive and Negative Feedback Difference
Positive- rare in the body, result of sudden occurrence (or amplifies a change from
normal point)
Example would be:
-birth
-blood clotting
-Increases the original stimilus
-milk production until baby is done feeding
-uterine contractions during birth
-fever (virus/bacteria, body heats self to get rid until enemy is destroyed)
Negative-Most homeostatic mechanisms are negative- effect is to shut off or reduce
original stimulus-
Example would be:
-heart rate
-blood pressure
-blood gluclose
-body temp
-oxygen levels in the blood
-thirst sensensation
feedback mechanism that detect change in environment
receptor
The receptor senses environmental stimuli, sending the information to the integrating
center.
Homeostasis
The ability of a system or living organism to adjust its internal environment to maintain a
stable equilibrium, such as the ability of warm-blooded animals to maintain a constant
body temperature.
What is the CONTROL CENTER for Homeostasis
Determines the level for a variable, analyzes info, determines appropriate response-
send along efferent pathway to the effector
Homeostatic control mechanisms have at least three interdependent components: a
receptor, integrating center, and effector.
What is thermoregulation
--body process that balances heat production and heat loss
maintain body's regular temperature- 37 degrees C 98.6 degrees F
-Internal thermoregulation contributes to animal's ability to maintain homeostasis within
a certain range of temperatures. As internal body temperature rises, physiological
processes are affected, such as enzyme activity.
,What is the process for thermoregulation
-in response to varying body temperatures, processes such as enzyme production can
be modified to acclimate to changes in the temperature.
-Endotherms regulate their own internal body temperature, regardless of fluctuating
external temperatures, while ectotherms rely on the external environment to regulate
their internal body temperature.
-Homeotherms maintain their body temperature within a narrow range, while
poikilotherms can tolerate a wide variation in internal body temperature, usually
because of environmental variation.
-Heat can be exchanged between environment and animals via radiation, evaporation,
convection, or conduction processes.
Definition of ischemia
deficient supply of blood to a body part (such as the heart or brain) that is due to
obstruction of the inflow of arterial blood.
function of lysosomes
-digest/break down food, waste, and broken parts
- A lysosome is an organelle containing digestive enzymes which it uses to function as
the digestion and waste removal for cells, food particles, bacteria, etc.
function of peroxisomes
-oxidation of toxic molecules
-oxidating fatty acids and amino acids into H202 peroxide, which is then broken down
into h20 and 02 by the enzyme catalase
function of ribosomes
-protein synthesis
-Ribosomes are a cell structure that makes protein. Protein is needed for many cell
functions such as repairing damage or directing chemical processes. -Ribosomes can
be found floating within the cytoplasm or attached to the endoplasmic reticulum.
function of mitochondria
-Cellular respiration, makes ATP.
-The most prominent roles of mitochondria are to produce the energy currency of the
cell, ATP (i.e., phosphorylation of ADP), through respiration, and to regulate cellular
metabolism. The central set of reactions involved in ATP production are collectively
known as the citric acid cycle, or the Krebs cycle.
function of golgi apparatus
-Modify, sorts and packages proteins and other materials from the ER for starage in the
cell or secretion outside the cell
-It is also involved in the transport of lipids around the cell, and the creation of
lysosomes. The sacs or folds of the Golgi apparatus are called cisternae.
The process of DNA to RNA
-transcription
-Transcription takes place in two broad steps. ... The pre-messenger RNA is then
"edited" to produce the desired mRNA molecule in a process called RNA splicing.
What role does DNA and RNA play in protein initiation
Ribosomal RNA (rRNA) associates with a set of proteins to form ribosomes. These
complex structures, which physically move along an mRNA molecule, catalyze the
, assembly of amino acids into protein chains. They also bind tRNAs and various
accessory molecules necessary for protein synthesis.
Difference between protein primary, secondary, and tertiary structures in
structure and function
-Primary structure is the order in which what amino acid is bound the other with a
peptide bond. This is coded for by the order of codons in a gene.
-Secondary structure is how the chains on amino acids interact with each other to form
beta barrels and alpha helixes. This structure is determined by hydrogen bonds
between the different amino acids.
-Tertiary structure is when the secondary structures interact with each other through
disulphide bonds, hydrogen bonds, hydrophobic/hydrophilic interactions etc. This is all
determined by the placement of certain amino acids within the proteins secondary
structure.
functions of microtubules, tubulin, microfilaments, and intermediate filaments
- Microtubules are hollow, fibrous shafts whose main function is to help support and give
shape to the cell. They also serve a transportation function, as they are the routes upon
which organelles move through the cell.
-Microtubules function in many essential cellular processes, including mitosis. Tubulin-
binding drugs kill cancerous cells by inhibiting microtubule dynamics, which are required
for DNA segregation and therefore cell division.
-functions are primarily mechanical and, as a class, intermediate filaments are less
dynamic than actin filaments or microtubules. Intermediate filaments commonly work in
tandem with microtubules, providing strength and support for the fragile tubulin
structures.
Difference between metaphase, Prophase, interphase, and G phase
-Metaphase-the second stage of cell division, between prophase and anaphase, during
which the chromosomes become attached to the spindle fibers.
-Prophase the first stage of cell division, before metaphase, during which the
chromosomes become visible as paired chromatids and the nuclear envelope
disappears. The first prophase of meiosis includes the reduction division.
-Interphase the resting phase between successive mitotic divisions of a cell, or between
the first and second divisions of meiosis.
-G phase- is the first of four phases of the cell cycle that takes place in eukaryotic cell
division. In this part of interphase, the cell synthesizes mRNA and proteins in
preparation for subsequent steps leading to mitosis. G1 phase ends when the cell
moves into the S phase of interphase.
Difference between Desmosomes, tight junctions, and Gap junctions
-Desmosomes- a structure by which two adjacent cells are attached, formed from
protein plaques in the cell membranes linked by filaments.
-Tight junctions- a specialized connection of two adjacent animal cell membranes such
that the space usually lying between them is absent.
-Gap Junctions-Gap junctions allow the exchange of ions, second messengers, and
small metabolites between adjacent cells and are formed by two unrelated protein
