BIO 225 Exam 1 umich Questions With
Correct Answers
Nervous system - ANSWER Electrical signaling, rapid but transient
Endocrine system - ANSWER Chemical signaling, slow but sustained.
Positive feedback - ANSWER Stimulus triggers mechanisms that amplify the
response and reinforces the stimulus.
I.e. parturation - stimulus: uterus distorted - receptors: stretch receptors of
uterine walls - control center: oxytocin release sends commands to - effectors:
muscles in uterine wall contract - response: contration and further distortion of
uterus - back to recepters: stretch receptors of uterine wall
And!! Action potential generation (initial trigger: opening of Na channel,
reduction of membrane voltage, activating voltage gated Na channels to open
further)
Phenotypic plasticity - ANSWER Single genotype generates more than one
phenotype depending on environmental conditions
Phenotype - ANSWER Is a product of genotype and its interaction w the
environment
Adaption - ANSWER Change in a pop over evolutionary time ( many generations)
Environmental factors affect phenotypic plasticity
Cellular adaption (sensory adaption)
Molecular adaption (sensory receptor adaption)
Energy categories - ANSWER Mechanical - movement of objects
Electrical - movement of charged particles
Thermal - movement of molecules
Chemical - within chemical bonds
Gradient - ANSWER A difference between two points
Difference in concentration
Diffusion - ANSWER Molecules disperse randomly in the available space
,Governs many biological processes:
Diffusion leads to random distribution of molecules (most likely high to low
conc.)
Diffusion of molecules is a source of energy
Electrochemical gradients - ANSWER Gradients are a form of energy storage
(potential energy)
Gradients across membranes can be chemical, electrical or both
(electrochemical)
I.e. membrane potential - electrical gradient across a cell membrane. Changes
in membrane potential act as electrical signals
Can be used by ion channels to generate a signal
Senses - ANSWER Physical/chemical stimulation detection and converting to
electrical signal and brain processing
Temp - thermal energy to chemical. Physical
Vision - physical energy (photon)
Taste - chemical
Olfaction - chemical
Metabolic pathways - ANSWER Series of reactions that convert substrates to
products. Catalyzed by enzymes.
Synthesis (anabolic)
Degradative (catabolic)
Metabolism - ANSWER Sum of metabolic pathways for the synthesis and
breakdown of molecules
Biomolecules - ANSWER Proteins (made of amino acids)
Carbohydrates (most common : glucose)
Lipids
Nucleic acids
Proteins - ANSWER Contribute to cell structure and function
Mediate all cellular processes
Protein structure is coded in DNA
Carbohydrates - ANSWER "Hydrates of carbon"
, Many hydroxyl (-OH) groups
Glucose is the most common carbohydrate in animal diets. Major source of
energy
Energy metabolism
Glycolysis - ANSWER Glucose molecule broken down to make ATP (2 molecules)
Lipids - ANSWER All are hydrophobic (do not dissolve in water)
Carbon backbone
Used for energy metabolism, cell structure and signaling
I.e. fatty acids, triglycerides, phospholipids, steroids
Phospholipids - ANSWER Dominate biological membranes
Two classes of phospholipids in animal cells:
-phosphoglycerides: constructed from diacylglycerol. I.e. phosphocholine (PC)
& phosphoinositides (PI(4,5)P2)
-sphingolipids
Part hydrophobic, part hydrophilic
Steroids - ANSWER Unique structures
Cholesterol
Acetyl CoA - ANSWER Used in TCA cycle to make reducing molecules, these
molecules go through electron transport system to make ATP
Major user of ATP - ANSWER Na+/K+ ATPASE
Ion pumps are essential for maintaining conc. Gradients
Mitochodria - ANSWER Essential for ATP generation
Gene expression - ANSWER In the nucleus and cytosol
Endoplasmic recticulum - ANSWER Make proteins and lipids
Golgi apparatus - ANSWER A system of membranes that modifies and packages
proteins for export by the cell
Correct Answers
Nervous system - ANSWER Electrical signaling, rapid but transient
Endocrine system - ANSWER Chemical signaling, slow but sustained.
Positive feedback - ANSWER Stimulus triggers mechanisms that amplify the
response and reinforces the stimulus.
I.e. parturation - stimulus: uterus distorted - receptors: stretch receptors of
uterine walls - control center: oxytocin release sends commands to - effectors:
muscles in uterine wall contract - response: contration and further distortion of
uterus - back to recepters: stretch receptors of uterine wall
And!! Action potential generation (initial trigger: opening of Na channel,
reduction of membrane voltage, activating voltage gated Na channels to open
further)
Phenotypic plasticity - ANSWER Single genotype generates more than one
phenotype depending on environmental conditions
Phenotype - ANSWER Is a product of genotype and its interaction w the
environment
Adaption - ANSWER Change in a pop over evolutionary time ( many generations)
Environmental factors affect phenotypic plasticity
Cellular adaption (sensory adaption)
Molecular adaption (sensory receptor adaption)
Energy categories - ANSWER Mechanical - movement of objects
Electrical - movement of charged particles
Thermal - movement of molecules
Chemical - within chemical bonds
Gradient - ANSWER A difference between two points
Difference in concentration
Diffusion - ANSWER Molecules disperse randomly in the available space
,Governs many biological processes:
Diffusion leads to random distribution of molecules (most likely high to low
conc.)
Diffusion of molecules is a source of energy
Electrochemical gradients - ANSWER Gradients are a form of energy storage
(potential energy)
Gradients across membranes can be chemical, electrical or both
(electrochemical)
I.e. membrane potential - electrical gradient across a cell membrane. Changes
in membrane potential act as electrical signals
Can be used by ion channels to generate a signal
Senses - ANSWER Physical/chemical stimulation detection and converting to
electrical signal and brain processing
Temp - thermal energy to chemical. Physical
Vision - physical energy (photon)
Taste - chemical
Olfaction - chemical
Metabolic pathways - ANSWER Series of reactions that convert substrates to
products. Catalyzed by enzymes.
Synthesis (anabolic)
Degradative (catabolic)
Metabolism - ANSWER Sum of metabolic pathways for the synthesis and
breakdown of molecules
Biomolecules - ANSWER Proteins (made of amino acids)
Carbohydrates (most common : glucose)
Lipids
Nucleic acids
Proteins - ANSWER Contribute to cell structure and function
Mediate all cellular processes
Protein structure is coded in DNA
Carbohydrates - ANSWER "Hydrates of carbon"
, Many hydroxyl (-OH) groups
Glucose is the most common carbohydrate in animal diets. Major source of
energy
Energy metabolism
Glycolysis - ANSWER Glucose molecule broken down to make ATP (2 molecules)
Lipids - ANSWER All are hydrophobic (do not dissolve in water)
Carbon backbone
Used for energy metabolism, cell structure and signaling
I.e. fatty acids, triglycerides, phospholipids, steroids
Phospholipids - ANSWER Dominate biological membranes
Two classes of phospholipids in animal cells:
-phosphoglycerides: constructed from diacylglycerol. I.e. phosphocholine (PC)
& phosphoinositides (PI(4,5)P2)
-sphingolipids
Part hydrophobic, part hydrophilic
Steroids - ANSWER Unique structures
Cholesterol
Acetyl CoA - ANSWER Used in TCA cycle to make reducing molecules, these
molecules go through electron transport system to make ATP
Major user of ATP - ANSWER Na+/K+ ATPASE
Ion pumps are essential for maintaining conc. Gradients
Mitochodria - ANSWER Essential for ATP generation
Gene expression - ANSWER In the nucleus and cytosol
Endoplasmic recticulum - ANSWER Make proteins and lipids
Golgi apparatus - ANSWER A system of membranes that modifies and packages
proteins for export by the cell
