Exam One: Learning Objectives Flashcards
1
Q
What is the reason for homeostasis?
A
organisms maximize their chances of survival by maintaining homeostasis
2
Q
How is homeostasis maintained?
A
control theory
3
Q
__ needs to be added to the system for homeostasis to be maintained
A
energy
4
Q
Define entropy
A
tendency for all matter and energy in the universe to evolve toward a state of inert uniformity
5
Q
Contrast entropy and homeostasis
A
homeostasis is the tendency of biology to fight entropy to maintain internal equilibrium by adjusting its physiological process
6
Q
Differentiate mechanistic and evolutionary physiology?
A
mechanistic - how does it work
evolutionary - why does it work?
7
Q
Define an adaptation
A
an alteration or adjustment in the structure or behavior by natural selection
8
Q
T/F: every observable trait is an adaptation
A
FALSE - must be tested
9
Q
Evolution shapes __
A
physiology
10
Q
Define evolution
A
process that allows populations of organisms to adapt to their environment; changes in allele frequencies of a gene, of a population over time
11
Q
What are three major factors animals need to deal with in their environment?
A
Temperature, oxygen, and water
12
Q
Describe the relation of temperature and environment
A
important for determining the rates of chemical reactions and the actions of enzymes in biological systems
13
Q
Describe the relation of oxygen and environment
A
animals need oxygen for metabolic energy (to form ATP)
14
Q
What are two environments that impact oxygen?
A
high elevation and water
15
Q
Organisms may ___ or __ in respect to their environments
A
regulate; conform
16
Q
Discuss the pros and cons of regulation
A
cells can function independently from the environment but costs a lot of energy
17
Q
Discuss the pros and cons of conformity
A
energetically cheap; cells are subject to changes dependent on environmental conditions
18
Q
organisms can _- to the environment or __ it
A
conform; regulate
19
Q
What are the three major time frames of physiological responses?
A
acute, acclimatization, and adaptation
20
Q
Define the acute response
A
temporary, immediate response
21
Q
What are examples of an acute response?
A
movement, inflammation, cell stress response, and adjustment of ventilation/ heart rate
22
Q
Define the acclimatization response
A
reversible physiological adjustment over several days
23
Q
What are examples of an acclimatization response?
A
adjustment of metabolic rate, lung capacity, or makeup of cell membrane
24
Q
Define the adaptation response
A
permanent physiological adjustments over evolutionary time
25
__ can happen within an animals life time but __ can only occur between generations
acclimatization; adaptation
26
Which physiological response is recorded in DNA?
only adaptation
27
Adaptation is often, but not always, pronounced __
phenotypically
28
___ can maintain in a species long enough for genetic __ to occur
acclimatization; adaptation
29
__ is usually reversible; but adaptation is __
acclimatization; non-reversible
30
What is the function of the plasma membrane?
the barrier between the cell and the environment
31
Membrane function depends on __
fluidity
32
Membrane fluidity depends on __ of the __ tail
saturation; hydrocarbon
33
Membranes have embedded __ which provide __
proteins; functionality
34
What are the three kinds of plasma membrane proteins?
channels and transporters
enzymes
receptors
35
Define an enzyme
facilitate chemical reactions; required to maintain virtually every tissue and function
36
an enzyme catalyzes the reaction in its __ __
active site
37
The greater the lowering of activation energy and faster the enzyme can change shape, the greater the __
catalytic effectiveness (kcat)
38
At high substrate concentrations, all enzymes are engaged and this ___ __ reaches its limit
reaction velocity (vmax)
39
__ of the reaction is proportional to __ concentration
velocity; substrate
40
Km is equal to?
substrate concentration at 1/2 vmax
41
Define enzyme-substrate affinity (Km)
affects velocity as well, in addition to substrate concentration
42
What are the four factors that influence reaction velocity?
1. number of active enzyme molecules
2. concentration of substrate
3. enzyme-substrate affinity (Km)
4. Catalytic effectiveness (Kcat)
43
Kcat describes how __ the enzyme is
fast
44
Define a ligand
other molecules that bind with enzymes/ proteins; molecule that binds specifically and non-covalently to the receptor
45
What is signal transduction?
responding to an extracellular signal by altering cell function
46
Signal transduction is a sub process of ?
cell signaling
47
What are the four categories of receptors?
ligand-gated channels
G protein coupled
enzyme/ enzyme linked
intracellular
48
Define signal reception
detecting an extracellular signal
49
Describe ligand-gated channels.
ligand is released and binds to receptor, receptor opens channel permitting ion exchange between the cell and extracellular environment
50
Describe G protein-coupled receptors
a ligand (first messenger) binds to a G protein-coupled receptor on the cell membrane, receptor changes conformation, which activates a G protein and usually targets an enzume, which produces a secondary messenger (cAMP) which carries out signal transduction
51
Describe enzyme or enzyme linked receptors
ligand binds to receptor, which is bound to an enzyme or itself is an enzyme, results in activation of catalytic site of the enzyme across the membrane, resulting in production of a second messenger (cGMP)
52
Describe intracellular receptors
a non-polar ligand (e.g. steroid hormone) enters and crosses the plasma membrane and enters the cell, the receptor for this ligand is either in cytosol or in nucleus, once ligand is bound to intracellular receptor; complex becomes an active transcription factor, which proceeds to activate specific primary response genes
53
How does signal amplification occur during transduction?
during the transduction pathway, many reaction steps result in the production of many product molecules, waterfall of exponential proteins/ enzymes
54
Describe an amplification cascade
single protein kinase 1 phosphorylates four protein 2 kinase which phosphorylate 16 protein kinase 3 and so on
55
Cell signaling often involves both a __ __ and a __ __
secondary messenger; phosphorylation cascade
56
What are the two processes of cell signaling
signal reception and signal transduction
57
Define signal reception
detecting an extracellular signal
58
What is cell signaling?
how cells tell each other what to do
59
Gene knockout is the ultimate __ __ approach
bottom up
60
Candidate proteins go with a ___ __ approach
top down
61
Describe a top down approach
animal function to tissue function to tissue-specific proteins to genes
62
Describe a bottom up approach?
Genes to tissue-specific proteins to tissue function to animal function
63
DNA microarray is an a tool of?
transcriptomics
64
Genomic sequencing is a tool of?
genomics
65
2D protein gel electrophoresis is a tool of?
proteomics
66
proteomics is the study of __
phenotype
67
NMR is an example of?
metabolomics
68
Describe human development with rats
human brain developed in matter of days, more sigmoidal
rat brain matter of days, more exponential
69
Rats place a high emphasis on what development?
brain and reproductive
70
Humans place the highest emphasis on __ development and the lowest on ___.
brain; reproductive
71
Define phenotypic plasticity
the ability of an organism with a fixed genotype to display two or more different phenotypes
72
Phenotype of adults of the same species can be different depending on their __ during __ (describes phenotypic plsticity)
environment; development
73
Phenotypic plasticity may differ due to (3) things
environmental stress, time of year of development, social
74
What is an example of stress in phenotypic plasticity?
having a more nurturing youth leads to taller children and earlier secondary development
75
What is an example of seasons in phenotypic plasticity?
insects differ in color dependent on seasonal development - darker in spring for heat
76
What is an example of social in phenotypic plasticity?
locust are solitary or gregarious depending on density; see locust, means lack of food, will become gregarious and swarm
77
What is an epigenetic marking?
markings with no changes in DNA sequence that are transmitted during replication
78
Epigenetic marking is often initiated by __ conditions via programmed control systems or chemical or physical forcing
environmental
79
What is DNA methylation?
explains how our genome can be directly influenced by the environment and passed on to future generations
80
What is the result and mechanism of DNA methylation?
addition of CH3 to cytosine results in silencing of genes
81
Epigenetic modification can be due to two mechanisms.
histone modification and methylation
82
Define passive transport
transport across a membrane that does not require energy (ATP)
83
Define active transport
requires ATP
84
Na+ and cl- ions are higher concentrations __ a cell
outside
85
K+ is higher in concentration __ a cell
inside
86
Ions travel through __ across the membrane
diffusion
87
Electrical gradients provide __ energy
potential
88
Both a concentration and electrical gradients point __ into the cell and __ out of the cell
Na
K
89
__ is near electrochemical equilibrium in the cell because its chemical gradient points __ and its electric gradient points __
Cl
inward; outward
90
Facilitated diffusion utilizes __ binding to __ proteins but is still __ and thus always occurs in the direction of __ equilibrium
reversible
transporter
electrochemical
91
What determines diffusion rates?
J = D (c1-c2)/x
92
Non-polar molecules (__ hormones) can dissolve in __ and this readily __ across membranes while others (__) cannot and thus require ___
steroid
lipids
diffuse
ions
channels
93
Define ion channels
large protein complexes that permit transport of only select ions through passive mechansims
94
What are the (4) types of ion channels?
voltage gated
strech-gated
phosphorylation-gated
ligand-gated
95
Define osmosis
movemment of water down its own concentration gradient
96
What are colligative properties defined by?
the number of dissolved solutess
97
Osmotic pressure is __ in water with __ dissolved solutes
higher; more
98
Water tends to move from __ to __ osmotic pressure
low; high
99
In freshwater fish, osmotic pressure is __ in the fish than in the pond water
higher
100
Sodium potassium pump is an example of?
primary active transport
101
Sodium potassium pump uses __ to transport __ Na+ _ and _ K+ _
3 in
2 out
102
What is an example of secondary active transport?
Na+/ glucose co-transporter
103
Secondary active transport is dependent on?
the electrochemical gradient generated by primary active transport
104
What is the function of lipids?
cell membranes, myelin, storage, waterproof, insulation
105
Lipids are stored?
in the bodies of animals as energy source,
106
__ has the greatest energy density of macronutrients
fat
107
Animals and plants can __ fatty acids from carbohydrates, proteins, and from other fatty acids
synthesize
108
Define fatty acids
chains of carbon atoms which aresaturated or unsaturated
109
What is the difference between saturated and unsaturated bonds?
saturated - no double bonds
110
What are essential fatty acids?
fatty acids that cannot be syntehsized by the body; those that have a double bond in the third and sixth bond away from the methyl end
111
What are the functions of proteins?
enzymes, muscles, antibodies, hormones, globins, membrane proteins
112
Proteins are __ stored in the bodies as an energy and nutrient source; __ or __
NOT
use it lose it
113
Carbohydrates are __ essential but still __ of energy
not
full
114
In vertebrae, most digestion takes place in the __ which includes the __
foregut
stomach
115
What are the major digestive proteins in the foregut?
pepsins
116
Pepsins make?
pepsinogens
117
__ molecules require __ to pass through cell membranes
polar; transporters
118
What are an example of polar molecules?
monosaccharides, amino acids, and water soluble vitamins
119
Some species harbor communities of __ __ and are able to digest __ and other molecules that animals cannot
fermenting microbes
cellulose
120
What are the three steps of foregut fermenters?
1. digestion of cellulose
2. synthesis B vitamins and essential amino acids
3. uptake of nitrogen
121
What is indigestible ?
cellulose
122
B vitamins and essential amino acids can be absorbed in the?
midgut
123
Hindgut fermenters can't obtain nutrients so they?
eat their feces
124
Fat soluble molecules is predominately mediated by __ diffusion because fats can readily pass __ __ cell membranes
simple
non-polar
125
lipid soluble molecules require __ to escort them throughout the body
lipoproteins
126
LDL is __ cholesterol and HDL is __ cholesterol
bad; good
