biomed week 6 Flashcards
1
Q
what is mutarotation
A
when linear monosaccharides take on a cyclic form they have additional “alpha” or “beta” designation
2
Q
monosacharides form cyclic structures when ….
A
one of their alcohol groups reacts with the aldehyde or ketone group
3
Q
linear monosaccharides are only found when ….
A
interconverting between various cyclic forms
these conversions = mutarotation
4
Q
what is the favoured D glucose mutarotation alpha or beta?
A
beta
5
Q
what is a nucleophile
A
attracted to the nucleus
- usually a negative charge
ex. water
6
Q
what is a electrophile
A
usually have a positive charge
ex . H+
7
Q
where can oxidation happen in redox reactions of glycoside formation
A
terminal CH2OH abd or the aldehyde end of straight chain forms
8
Q
where does reduction happen in redox reactions of glycoside formation
A
can happen at the aldehyde end of straight chain forms
9
Q
is D glucuronic acid hydrophobic or hydrophilic why?
A
hydrophillic because its very electronegative creating a polar structure
10
Q
stereoisomers are
A
same atoms in the same order but different spatial arrangement (must have chiral carbon
11
Q
enantiomers are
A
mirror images of each other
given D or L designations based on position of OH group attached to the chiral carbon C atom furthest from the aldehyde or ketone group
12
Q
structural isomers are
A
same atoms but not the same order
ex
C1 C2 glucose vs fructose
13
Q
diastereomers are
A
not mirror images
may or may not be epimers
(epimers differ at only 1 chiral carbon)
14
Q
what carbon is the ketone group on
A
C2
15
Q
stereoisomers can be ……. or …..
A
diastereosomers or enantiomers
16
Q
any stereoisomer that is not an enantiomer is a ….
A
diastereomer
17
Q
diastereomers may or may not be
A
epimers
18
Q
what is an epimer?
A
vary in one position for the placement of OH group
19
Q
what is galactose
A
an epimer of glucose, often attached to lipids to make glucolipids or to protiens to make proteoglycans and glycoprotiens
20
Q
lactose is composed of …….. and …… in a …… linkage
A
galactose and glucose in a beta 1-4 linkage
21
Q
how do you identify a reducing sugar?
A
if it has a OH group on its anomeric carbon
has free aldehyde and ketone groups
- nothing attached to the OH
22
Q
describe the non reducing end
A
C1 carbon is attached to the next monosaccharide
23
Q
what do more branch points create
A
more non reducing ends
24
Q
which way is an alpha sugar facing
A
downwards
25
which way is the alpha sugar facing
upwards
26
what is the purpose of homopolysaccharides
cellulose function
- provides structure to plant cells
27
what is the difference between the homopolysaccharides and heteropolysaccharides
homopolysaccharides are made up of ....... type of monosaccharide, where as heteroppolysaccharides aree made up of .... type of monosaccharide
1
more than one type
28
name three common monosaccharides found in GAGs
glucose , idose , galactose
29
what are some common monosaccharide derivitives in GAGS
any glucose and galactose
amino groups
acid groups
acetyl groups
sulfates
30
what is mucopolysaccharidosis ? and what is an example?
pathology associated with excessive accumulation of proteoglycans due to missing or defective lysosomal enzymes
hurlers syndrome
- autosomal recessive
- defficient enzyme L-iduronidase
- cant remove iduronic acid
31
reducing structures are capable of ..... but can not have
capable of opening into straight chain form
anything attached other than the OH attached to the anomeric C1 carbon
32
methylated OH means ......
stable and locked into cyclic form
33
a phosphate is a better leaving group than a hydroxyl so adding a phosphate to a monosaccharide makes it more .... what else can a phosphate group do?
reactive
trap in the cell
34
why are monosacharride sulfate esters important
at physiological pH these become negatively charged
- negative charges attract water
makes Connective tissue less dense so it can occupy 1000s of times as much space
35
glycoside sugars are when the OH group on the anomeric carbon is replaced by an .... forming a .....
alcohol
glycosidic link
36
what is an example of a cardiac glycoside
digoxin
- foxglove
37
what are two important monosaccharide derivatives
deoxy sugars and amino sugars
38
what is important about deoxiribose sugars
OH group is replaced with just a H
39
what is important about amino sugars
OH group is replaced with an amino group which may also be acetylated
40
disaccharides are formed when
two sugars join via a glycosidic link
41
in disaccharides, alpha and beta designations come from .....
OH positions at C1 of the first and second monosaccharides
42
what is the difference between oligosaccharides and polysaccharides
oligo - small number of monosaccharides linked by glycosidic bonds
poly - larger number of monosaccharides linked by glycosidic bonds
43
homo vs heteropolysaccharides
homo= all the sam
heter = different
44
examples of homosaccharides
all the same monosaccharides
storage and structural
only one reducing end
amylose , amylopectin, glycogen
45
examples of heterosaccharides
all different monosaccharides
structural
GAGS (glycoaminoglycans)
- chrondrotin sulfate
- dermatan sulfate
46
what is a glycoconjugate
adding mono, di or polysaccharides to other molecules creates glycoconjugates
47
what is the significance of the branches in homosaccharides
can store more compact with many more ends that can be broken down
48
acidic sugars in most GAGS is
glucuronic acid
49
amino sugars in most GAGS is
glucosamine or galactosamine
- often acetylated and sulfated
booth epimers
50
acid groups and sulfates have what charge?
negative
51
negative chrages in GAGs create
- slippery texture due to charge repulsion
- a large volume as GAGS are hydrated
- resilience as tissue can be squished when water is pushed out
52
how are carbs attached to protiens?
O- or N- glycosidic links
53
what os an O- glycosidic link
carb attached through "O" on a serine or threonine R group
(ogligosaccharides are often atatched via the O)
54
what is an N glycosidic linkage
carb attached to the protein through an N on asparagine R group
55
proteeoglycans consist of various
GAGs attached to core protiens via an O- glycosidic link
56
what is the physiology of proteoglycans
- located in extracellular matrix
- contribute to support and elasticity to tissues
57
what types of monosaccharides are commonly found in the mono, di or oligosaccharide attachments?
N-acetylglucosamine , N acetylgalaxtosamine , mannose , galactose
58
what kind of carbs are not found in glycoprotiens
glucarionic acid
59
what is the physiology of glycoprotiens
often attached to the membranes projecting externally from the cell
60
what is mass balance
Mass balance is a conservation principle in which the mass entering a system must equal the mass leaving the system, accounting for any changes in mass within the system.
61
what happens to mass balance when you decrease the amount of Z removed
the concentration gets higher
62
what is clearance in mass balance
the volume of a fluid that has been completely cleared of a substance
63
what happens when you damage clearance mechanisms and clearance drops
blood concentrations change
- flow rate and concentration of bladder stay the same but concentration of reservoir increases (doubles)
64
how do you calculate the clearance
clearance = concentration of Z in the bladder X flow (1 l/min) / concentration of Z in the reservoir
65
if you cut the clearance in half, what happens to the concentration in the reservoir?
it doubles
66
what is boyles law
only applies to gases
- if you increase the pressure in a container with a gas in it, the volume of the gas will decrease
- gas and volume are inversely related
P1V1=P2V2
67
how do we change the pressure in the alveoli?
increase the volume
boyles law
68
what is laplaces law
circular or spherical or cylindrical objects in the body
- contain gas or fluid which can extert pressure against the walls
69
what is the laplaces law equation
tension = pressure x radius / thickness
70
in laplaces law, when the thickness increases
more muscle fibers , less tension on one specific fiber and more widespread tension
71
tension in laplaces law increases when radius
increases
72
tension in laplaces law increases when pressure ....
increases
73
tension in laplaces law increases when thickness
decreases
74
what is an aneurysm
a pathological increase in the diameter of a blood vessel
75
when the diameter of the blood vessel increases the
higher the strain (tension)
76
dialated cardiomyopathy - increased diameter of the left ventricle
very stressed heart, high tension in the ventricle, heart has to pull harder against the tension
77
what is equilibrium in homeostasis
when a process proceeds in the forward direction at the same rate - non net change occurs
78
what is the homeostasis dynamic steady state
when a process of system exerts energy to maintain a particular state
- this state is not at equilibrium
79
what is the regulated variable in homeostasis
a parameter that is measured in the body with sensors and is kept within a set of limits
limit = between a low and a high range
- limit is what homeostasis is devoted to regulating
80
what is the homeostasis control centre
has a controller and an error detector
error detector - calculates the difference between the set point value of the regulated variable and the actual value of the regulated variable and sends an error signal to the controller
controller - sends output signals to effectors that can change the regulated variable depending on data from the error detector
81
what is the set point in homeostasis
the range of values of the regulated variable that the system tries to maintain
82
what is the non regulated variable in homeostasis
effectors usually change the non regulated variable in order to bring the regulated varible closer to the set point
83
is negative feedback always homeostasis
negative feedback can be homeostasis but is not always... there is no control centre, set point , error signal or regulated variable
84
what are the two main baroreceptors
carotid arteries and the arch of the aorta
pressure drops, message sent to the brainstem via nerves
- activated sympathetic nervous system to release epinephrine , norepinephrine
85
what are the 6 key components in blood pressure regulation in homeostasis
sensor
error detector
the controller
the effector
input and output signals
the non regulated variables
86
true or false
homeostatic mechanisms only turn on when the regulated variable is outside the set point
false
most sensors usually constantly deliver information to the control centre
the controller responds more intensely with a larger error signal but its almost always sending input to the effectors at some basal rate
87
are homeostatic systems isolated?
no, they tend to overlap
88
what is positive feedback
output of a system is fed back in a manner that tends to increase that systems output
tends to result in an exponential increase in the output until a limiting event is reached
89
what is a common example of positive feedback
pregnancy
90
what are the basic mechanisms of the parturition reflex
babys head presses on and thins the cervix
cervical thinning and stretching is detected by mechanoreceptors and transmitted to the brain
the hypothalamus releases oxytocin in response
oxytocin causes uterine contraction, forcing the baby against the cervix
91
what are feed forward loops
systems where changes in a regulated variable are anticipated and the controller pro actively activates an effector
92
cerebral cortex controls
voluntary control of respiratory rate
93
hypothalamus regulates
respiratory rate based on emotional state , pain, body temp set points
tells the brainstem to change ventilation
94
proprioceptors function
when your muscles and joints move, sends signal to your brainstem
changes ventilation in anticipation of increased MSK oxygen and carbon dioxide exchange needs
95
chemoreceptors function
increase ventilation when arterial oxygen drops and carbon dioxide increases
96
how do cells signal to eachother
contact
- membrane recepetors
paracrine
- cell A produces a soluble messanger which diffuses to a cell "B" , binding to cell membrane receptor on cell B creating an intracellular signal
97
what are the four major types of cell signalling
contact dependant
paracrine
synaptic
endocrine
98
what are direct contact signals good for
embryologic development, immune signalling, limiting / organizing growth
99
what is paracrine signalling good for
short distances
immune defence
signals of local damage
regulation of growth / cell division
local regulation of blood flow
100
what is a major example of endocrine signalling
hypothalamic-pituitary system
101
how is the hypothalamus connected to the pituitary gland
sits under the thalamus via a vascular stalk
102
what is the general model of the hypothalamic-pituitary system
hypothalamic signal stimulates pituitary cells
pituitary cells release a hormone
hormone acts on another gland (usually endocrine)
target gland secretes larger quantities of a hormone
general systemic response
103
the hypothalamus secretes releasing hormones into ....
1 set of capillaries
which travel down to anterior pituitary and modulate hormone secretion from those cells
104
hypothalamic neurons project to the ...
posterior aspect of the pituitary
105
what are the major hormones secreted in the posterior pituitary
ADH and oxytocin
- direct target on tissues not on other glands
106
what does ADH control?
how is its secretion controlled?
anti diuretic hormone controls water balance in the body
controlled by the osmolarity of the blood
- when the blood is more concentrated then ADH is secreted
107
what is blood osmolarity detected by
osmorecptors in the hypothalamus
108
where is thyroid hormone release regulated
hypothalamus in response ti cardiovascular parameters and metabolic parameters
- also released in a particular rhythm to facilitate growth of the organsim
109
decreased thyroid hormone stimulates ........
which then stimulates
....
which stimulates
....
which increases
hypothalamus to release TRH
TRH stimulates anterior pituitary to release TSH
TSH stimulates thyroid gland to release thyroid
increases thyroid hormone
110
tyroid hormone negatively feeds back on the ...... and the ....
anterior pituitary and the hypothalamus
111
TSH negatively feeds back on the ....
hypothalamus
112
what is reverse transcriptase?
an enzyme that viruses would have to translate RNA into DNA to make new double stranded gap DNA
113
why does our body want to fix the gap DNA
because it does not recognize it is a virus
114
what is an example of Hep B
Gap DNA
115
what is an example of single stranded DNA viruses
paeavoviridae
