3. • Course Outline
• 1. Introduction
– Definition and Scope of Biochemistry
– The Cell and its organelles
– Water and Chemical bonds in biochemistry
– pH and biological buffer systems
• 2. Chemistry of amino acids and Proteins
• 3. Enzymes
• 4. Chemistry of CHO
• 5. Chemistry of Lipids
• 6. Metabolism of CHO
• 7. Metabolism of Lipid
3
5. • Definition and scope of biochemistry
– Biochemistry is the science concerned with the
chemical basis of life.
– Since cell is the structural and functional unit of living
systems
• Biochemistry can be defined as the science
concerned with the chemical constituents of living
cells and chemical changes and processes that
occur in cells and hence in living tissues and
organisms.
• Hence simply biochemistry is the chemistry of
living cells or tissues.
– Biochemistry is concerned with the entire spectrum of
life forms, from relatively simple viruses & bacteria to
complex human beings.
• By this definition, biochemistry encompasses large
areas of cell biology, of molecular biology, and
of molecular genetics. 5
6. • Definition cont’d…
– Biochemistry attempts to explain, in terms of biology
and chemistry, the two basic activities of living
organisms:
• Maintenance of the individual
• Perpetuation of the species
– To maintain the individual organism:
• Cells should be able to synthesize substances
called biomolecules (carbohydrates, lipids,
proteins, nucleic acids) that build up a living
organism, or degrade them when necessary.
• Cells should also be able to extract energy from
the food substances for various physiological
activities such as biosynthesis, active transport of
materials, muscle contraction etc.
6
7. • To perpetuate the species:
– Genetic information should pass from one generation
to the next i.e, DNA (the molecule that stores
genetic information) should replicate during cell
division and pass to the offspring.
• Biochemistry attempts to understand storage and
transmission of genetic information from
generation to generation at molecular level.
7
8. • Link to Clinical medicine
– All diseases has a biochemical basis b/se all diseases are
manifestations of abnormalities of molecules, chemical
rxns, or processes.
• Biochemistry has many important applications in
medicine such as understanding:
– Inborn errors of metabolism that occur due to
mutation in genes leading to deficiency of enzymes
that these genes encode
» such as phenyl ketoneuria, albinism, glycogen
storage diseases, lipid storage diseases etc.
– Pathophysiology of metabolic disorders like DM and
atherosclerosis and genetic diseaes.
– Nutritional problems
– Pharmacologic actions of drugs
– Application in diagnosis of diseases etc
• Therefore knowledge of biochemistry contributes to
diagnosis, prognosis and treatment of diseases.
8
10. • The cell and its organelles
– Cells are the fundamental structural and functional units of
living organisms.
• They can be considered as natural vessels for
biochemical reactions.
• They are of two major types:
– Prokaryotes (having no true nucleus).
» They rather have an irregularly shaped
region called nucleoid that contain the
genetic material and is not membrane
bounded.
» Include bacteria and blue green algae.
– Eukaryotes (having true membrane bounded
nucleus). Include all other living forms.
– A typical eukaryotic cell has three major components:
• 1) The cell membrane
• 2) The cytoplasm containing the cellular organelles and
• 3) The nucleus with the nucleolus in it
10
12. • The cell membrane
– Also known as
plasmalemma,
plasmamembrane or
cytoplasmic membrane.
– Composed of a
phospholipid bilayer
(outer and inner leaflets) in
which proteins are
embedded; hence the
name fluid mosaic
membrane.
– Function:
• It encloses the cell
and limits its size and
shape.
• Controls transport of
materials in and out of
the cell b/se it is
selectively permeable
and restricts the
exchange of polar
compounds. However
non polar molecules
can pass freely. 12
14. • The Cytoplasm
– Is the intracellular space, other than the organelles,
bounded by the plasma membrane.
– Filled with a jelly like fluid called the cytosol in which
the cellular organelles suspended.
• The cytosol contains many proteins most of which
are enzymes.
• It also contains glycogen in some tissues such as
the liver and muscle or fat droplets in adipose
tissues.
14
15. • The Nucleus
– Is the largest cellular organelle surrounded by a
double membrane called nuclear envelop/nuclear
membrane.
– It contains the nucleoplasm in which a complex of
nucleic acids and proteins distributed.
– The nucleus also contains enzymes for DNA
replication and transcription.
– The two membranes of the nuclear envelope join at
sites called nuclear pores which communicate the
nucleus with the cytoplasm.
– The nucleolus is a spherical structure in the nucleus
where assembly of ribosome occur
15
16. • The Cytoplasmic Organelles
– Mitochondria (singular mitochondrion)
• Are double membrane bounded organelle (the
outer and inner membranes).
– The two membranes differ in composition and
function:
» The outer membrane forms a smooth lipid
bilayer envelop and is freely permeable to
most substances through porin pores.
» The inner membrane is a highly
impermeable structure having high protein
content most of which are enzymes of the
electron transport chain.
» It forms invaginations called cristae, w/c
provide it a large surface area.
– The space within the inner membrane is called
as mitochondrial matrix.
16
18. • Function of Mitochondria:
– Mitochondria are the sites of intracellular
respiration, a process in which the energy released
from oxidation of fuel molecules is used for the
synthesis of ATP from ADP and inorganic phosphate
(Pi) using molecular oxygen.
– This occurs in the inner mitochondrial membrane
• Hence mitochondria is sometimes referred to as
“power house of the cell”.
18
19. • Function of Mitochondria cont’d…
– The mitochondrial matrix contains many proteins
majority of which are enzymes for:
• Oxidation of pyruvate, (β-oxidation), & TCA cycle,
• Gluconeogenesis, urea cycle and heme
synthesis occur partially in mitochondrial matrix.
• In addition, the matrix contains:
– NAD+ & FAD, ADP and Pi, mitochondrial RNA
and DNA that code for some mitochondrial
proteins (mtRNA & mtDNA) and
mitochondrial ribosomes.
19
20. • Endoplasmic reticulum
(ER)
– Is a network of
membranous tubules
within the cell.
– They are of two types:
Rough and Smooth
ER
• Rough ER is
studded with
ribosomes and
hence serves as
site of synthesis of
proteins to be
secreted out.
20
21. • Smooth ER lacks
ribosome:
– It has roles in
biosynthesis of lipids
(TAG & phospholipids)
and steroid hormone,
– Contains the cytochrome
P450 oxidative enzymes
and involved in
metabolism
(detoxification) of drugs
and toxic chemicals like
ethanol,
– Also involved in
glycogen storage in
liver and muscle.
– In muscle contraction &
relaxation: (sarcoplasmic
reticulum of skeletal mm,
release & recapture
Ca++).
21
22. • Ribosomes:
– Are nucleoprotein complexes which are made of a
non covalent association of ribosomal proteins and
ribosomal RNAs.
– They are not membrane bounded and are not usually
considered as sub cellular organelles proper.
• They are just supramolecular structures.
– Occur either attached to RER or free in the cytosol.
– They serve as site of protein synthesis in both
cases.
• The free ribosomes are site at which proteins
to be used intracellular are synthesized.
– Cells with high rate of protein synthesis have
prominent nucleoli & many ribosomes. Eg. liver
22
23. • Golgi apparatus
– Named for histologist
Camillo Golgi who
discovered it in 1898
– Is formed of a set of
stacked smooth
membranous saccules
called cisternae which
is generally divided
into three
compartments:
• the cis-Golgi
network;
• the medial Golgi
stacks; and
• the trans Golgi
network.
23
24. • Golgi apparatus cont’d…
– the cis (entry)-Golgi network: is often convex and
faces the RER;
– the medial-Golgi stacks is formed of few cisternae
between the cis & trans faces and
– the trans (maturing)-Golgi network: is often
concave and faces the apical plasma membrane.
24
25. • Function of Golgi apparatus:
– Involved in modifying, sorting, and distributing
proteins produced in the RER
• modifying (glycosylation, sulfation,
phosphorylation etc which are called post
translational modifications of proteins),
• sorting, and distributing proteins produced in
the RER to secretory vesicles, to the plasma
membrane or to lysosomes.
– Proteins transported out of the cell in secretory
vesicles which bud off from the golgi complex
by exocytosis.
– Golgi is found in all cells but is especially well
developed in cells that secrete materials:
• Plasma cells: secrete antibodies
• Pancreatic acinar cells: secrete digestive enzymes.
25
27. • Lysosomes
– Are single membrane bounded vesicles that bud off
from the Golgi apparatus.
– Contain about 40 different hydrolytic enzymes
including nucleases, phosphatases, glycosidases,
esterases, and proteases called cathepsins.
• Most of these lysosomal hydrolases have their
maximal activity near a pH of about 5.5 (acidic
compared to cytosolic pH = 7.2).
– The cytosolic components are protected from
these enzymes by the membrane surrounding
lysosomes.
• and b/se the enzymes have optimal activity at an
acidic pH, any leaked lysosomal enzymes are
practically inactive at the pH of cytosol and
harmless to the cell.
27
28. • Function of lysosomes:
– Involved in intracellular digestion and elimination of
unwanted material such as pathogens and
damaged or old organelles and recycling their
components.
– This intracellular digestion role of lysosomes is
central to a wide variety of body functions including:
• destruction of infectious bacteria and other
pathogens,
• recovery from injury,
• tissue remodeling,
• involution of tissues during development, and
• normal turnover of cells and organelles. 28
29. • Peroxisomes (Microbodies)
– Are single membrane
bounded organelles similar
in size to lysosomes but
bud off from
endoplasmic reticulum.
– Involved in oxidative
reactions using molecular
oxygen.
• but do not produce ATP
and do not participate
directly in cellular
metabolism unlike
mitochondria.
– Peroxisomal oxidative
reactions produce the
toxic chemical H2O2,
• which is either utilized
or degraded within the
peroxisome by catalase
to H2O and O2.
29
30. • Functions of peroxisomes
– Peroxisomes are involved in detoxifying toxic
substances in addition to the H2O2 produced by their
action.
• For e.g. ethanol consumed in alcoholic drinks,
oxidized to acetaldehyde by peroxisomes.
– They also function in oxidation of very long chain
fatty acids with 20 or more carbons to shorter chain
fatty acids,
– Also involved in conversion of cholesterol to bile
acids, and synthesis of ether phospholipids called
plasmalogens.
30
31. Cytoskeleton:
– Is a flexible network of
fibrous proteins extending
throughout the cytoplasm
of cells;
– Is a structure that gives
mechanical support to the
cell
– Composed of three types
of fibrous protein
components:
• Micro filaments/thin
filaments also called
actin filaments b/se
are composed of actin,
• Intermediate filaments
composed of different
fibrous proteins such
as α-keratin.
• Microtubules
composed of tubulin
31
33. • Function:
– Maintains structure or shape of the cell surface,
– Fixes the position of organelles or organizes
arrangement of subcellular organelles and
– Actin filaments and microtubules moves organelles,
and even move the whole cell
– Facilitate endocytosis and exocytosis,
– Microtubules function in mitosis and cytokinesis
(the process whereby a cell is partitioned into two
progeny cells).
33
36. • Water
– Is the most abundant and remarkable substance in living
systems whose properties are central to life
– Makes up ~ 70% of weight of most organisms.
• Hence in living cells biomolecules exist and interact in
an aqueous environment.
– It is the universal medium or solvent in living organisms
• As a solvent water solubilizes and modifies the
properties and function of biomolecules by forming
hydrogen bonds.
• It also acts as a medium in which
– the transport of nutrients in blood
– the enzyme catalyzed reactions of metabolism and
– the transfer of chemical energy occur.
– Two properties of water are especially important
biologically: Its polar nature and hydrogen bonding
capability
36
37. • The polar nature:
– Water is a polar
molecule with two lone
pair electrons on the
oxygen atom.
• The oxygen nucleus
draws electrons away
from the hydrogen
nuclei, which leaves
the region around the
hydrogen nuclei with
a net positive charge,
it self being more
negative making the
molecule polar.
37
38. • Hydrogen bonding (cohesive
forces):
– Due to the polar nature
water molecules form weak
intermolecular bonds
called hydrogen bonds in
addition to the covalent
bond between O and H.
• In a solid state each
water molecule forms 4
H-bonds with the
surrounding four water
molecules
• Whereas in a liquid
state each water
molecule forms less
number of H-bonds
with other water
molecules
– b/se some bonds
broken down as it
changes to liquid.
38
39. • Hydrogen bonds are central to life as water in liquid state
is:
– b/se it is these strong cohesive forces b/n water molecules
that make water to have high heat of vaporization and
exist in a liquid state at room To.
• water is by far the most common molecule that exists in
a liquid form at typical ambient temperature on earth.
• In general the polarity and H-bonding capability of water
confer it unusual physical properties such as:
– Low viscosity
– both cohesive & adhesive properties
– High specific heat capacity
– High melting point, High boiling point and High heat of
vaporization
• Living organisms have evolved means of exploiting
these properties of water and effectively adapted to
their aqueous environment.
39
41. • Chemical bonds in biomolecules
– Any living matter is composed of organic molecules
referred to as biomolecules.
• The major ones are: Proteins, Carbohydrates,
Lipids and Nucleic acids (RNA and DNA).
– Molecular interactions among biomolecules and with
their aqueous environment is mediated by two types
of chemical bonds:
• Covalent bonds and
• Non covalent interactions
– Major d/ce b/n the two is the bond energy (a
single covalent bond is far much strong
compared to a single non covalent bond).
41
42. • Covalent bonds:
– Are true chemical bonds formed by the sharing of a
pair of electrons between adjacent atoms.
• Important covalent bonds in biomolecules include:
– Peptide bonds = b/n amino acids in
proteins,
– Glycosidic bonds = b/n monosacharides in
oligo and polysaccharides and
– Ester bonds in fats
– Phosphodiester bonds b/n nucleotides in
DNA and RNA.
42
43. • Non covalent bonds:
– Are not true chemical bonds hence are called as
weak secondary bonds.
– Why are they important?
• i) Because of the dynamic nature of chemical
processes occurring in living cells such as
hormone-receptor interactions, enzyme-
substrate interactions, antigen-antibody
binding etc; readily reversible molecular
interactions are crucial.
• ii) Although non covalent bonds are individually
weak, are collectively strong when formed in larger
number and have a significant role in
– stabilizing the structures of proteins,
nucleic acids, polysaccharides and
supramolecular structures like membrane
lipids and ribosomes. 43
44. • There are four major non covalent bonds:
– Hydrogen bond,
– Electrostatic interaction (ionic bond or salt
bridge),
– Hydrophobic interaction and
– Van derwaals interaction.
• i) Electrostatic interactions:
– Are formed by eletrostatic attraction between two
oppositely charged ions.
– In living cells, there are a number of ionizable
chemical entities that bear
• a positive charge (e.g., amino, R–NH3
+) or
• a negative charge (e.g., carboxylic, R–COO-, -
PO4
-).
44
45. • ii) Hydrogen bonds:
– Are formed between an
electronegative atom
(usually oxygen or
nitrogen) and a
hydrogen atom
covalently bonded to
another
electronegative atom in
the same or another
molecule.
• Hence the H atom in
a H-bond is partly
shared between two
relatively
electronegative
atoms.
– Therefore
basically H- bond
is a kind of
electrostatic
bond. 45
46. • iii) Van der Waals interactions:
– Are formed b/n any two atoms in close proximity
within a molecule and are the weakest bonds.
– They are formed due to charge asymmetry around
an atom due to asymmetric distribution of
electronic charge around an atom.
– This charge asymmetry in turn acts through
electrostatic interactions to induce a complementary
charge asymmetry around its neighboring atoms.
46
47. • iv) Hydrophobic interactions:
– Based on their interaction with water biomolecules
can be classified as:
• Hydrophilic,
• Hydrophobic &
• Amphiphilic/amphipathic
– Hydrophilic (polar biomolecules) dissolve
readily in water because they can replace
energetically favorable water-water interactions
with even more favorable water-solute
interactions such as hydrogen bonds and
electrostatic interactions.
– Non-polar biomolecules (hydrophobic) in
contrast interfere with the existing favorable
water-water interactions and decrease entropy
(disorderedness) of the system hence are
poorly soluble in water.
47
48. • Therefore:
– In aqueous solutions,
hydrophobic molecules
tend to cluster together
to minimize the
energetically
unfavorable effects of
their presence and
• so they release some
of the water making
the system achieve
greatest
thermodynamic
stability.
– Such interaction
of non-polar
biomolecules in
aqueous
environment is
termed as
hydrophobic
interaction.
48
51. • Amphipathic molecules:
– Contains both polar and non-polar regions.
– When such compounds are mixed with water, their
polar and non-polar regions experience conflicting
tendency:
• The polar or charged, hydrophilic region interact
favorably with the solvent and tends to dissolve,
but the non-polar, hydrophobic region has the
opposite tendency, to avoid contact with water
(hydrophobic interaction).
– Such conflicting interactions of the two
opposing parts of amphipathic molecules is
particularly important in biological membranes
by stabilizing its amphipatic phospholipid
bilayer.
51
55. • Acids and Bases
– According to Bronsted-Lowry definition acids are
proton donors bases are proton acceptors.
– The measure of acidity or basic nature of a certain
solution is pH.
• It measures concentration of hydrogen ion ([H+])
• Mathematically pH = - log [H+].
– There is another concept called pOH w/c is closely
related to pH. pOH is a measure of concentration of
hydroxyl ion (OH-).
• Mathematically pOH = - log [OH-].
55
56. • Relation b/n pH and pOH
– pH and pOH are related by ion product of water also
called dissociation constant of water (Kw).
• Kw = [H+] x [OH-] = 10-14.
• [H+] x [OH-] = 10-14
• Taking –log of both sides of this equation:
• - log [H+] - log [OH-] = -log 10-14
• Simplified to pH + pOH = 14
• It is this relation of pH and pOH that leads us to the pH
range/scale w/c is 0 to 14
56
58. • Strong and Weak Acids & Bases
– Strong acids and bases completely ionized in aqueous
solution and concentration of the formed ions are equal to the
molar concentration of the strong acid or base.
• Ex. HCL, H2SO4, HNO3 etc are strong acids, NaOH, KOH
etc are strong bases.
– Where as weak acids and bases dissociate only partially in
aqueous solutions and the concentration of the formed ions are
not equal to the molar concentration of the weak acid or base
• Examples of weak acids of physiological importance include
acetic acid (CH3COOH) w/c is produced from acetyl CoA or
ingested as vinegar and other foods.
• H3PO4, H2PO4-, HPO42- and H2CO3 w/c all act as a buffer.
• Acetyl salicylic acid (ASA) not produced in the body but
ingested as a drug.
58
59. • Ka and pKa
– The strength of an acid or base is measured by its
dissociation constant K or by the pK
• For the acid HA the dissociation equilibrium is
given by HA ↔ A- + H+
• The dissociation constant Ka = [A- ] [H+]/ [HA].
– The larger the Ka the stronger the acid
• pKa = -log of Ka w/c is also measure of strength of
an acid.
– The lower the pKa the stronger the acid.
59
60. • Relation b/n pH and pKa (Henderson-Hasslbalch
equation)
– For the acid HA the dissociation equilibrium is given by
• HA ↔ A- + H+
• Ka = [A- ] [H+]/ [HA]
• [A- ] [H+] = Ka x [HA]
• Solving for [H+]
• [H+] = Ka [HA]/ [A- ]
• Taking –log of both sides
• -log [H+] = -log Ka - log [HA]/ [A- ]
• Simplified to pH = pKa - log [HA]/ [A- ].
• If we invert the- log [HA]/ [A- ] w/c involves
changing its sign gives what is called Henderson-
Hasselbalch equation. pH = pKa + log [A- ]/[HA].
– In more general terms it can be re-written as:
60
61. • Buffers
– Are mixtures of weak acids and their conjugate bases
or weak bases and their conjugate acids.
• Ex. mixture of CH3COOH (acid) and CH3COO- (base) in
dissociation of acetic acid; CH3COOH ↔ CH3COO- + H+
– Buffers resist changes in pH when strong acids (H+)
or strong bases (OH-) are added.
– The amount of H+ or OH- that can be neutralized by
any buffer, without change in pH is termed as
buffering capacity.
• Buffering capacity is ‘the number of grams of a strong acid
or a strong base required to bring about a change of one pH
unit in one liter of a buffer solution’.
61
62. • Buffering capacity
depends on
concentration of the
components of the
buffer and it is maximum
when [proton donor] =
[proton acceptor].
• This occurs at the mid
point of titration of a
weak acid with a strong
base (titration curve).
• At this point pKa of an
acid is equal to the pH of
the medium,
Titration curve of acetic
acid pKa =4.76
62
63. • The fact that when [proton donor] =
[proton acceptor], pH = pKa can be proved
from Henderson-Hasselbalch equation:
– pH = pKa + log [proton acceptor]/[proton donor].
– when [proton donor] = [proton acceptor],
• log [proton acceptor]/[proton donor] = 1. Hence the
equation becomes ,
• pH = pKa + log 1
• pH = pKa + 0
• ⇒pH =pKa
63
64. • Therefore from the above fact, a buffer system with
pKa value close to the physiological pH w/c is 7.4 is
a good buffer system in our blood.
– E.g. acetic acid/acetate conjugate is not a good buffer
system in blood because the pKa of acetic acid 4.75
is far from 7.4.
• In mammals (including man) the important buffer
systems are:
– the bicarbonate buffer system and
– the phosphate buffer system.
– the amino acid and protein buffer systems
64
65. • The bicarbonate buffer system:
– It is the major buffer system in blood plasma;
– consists of carbonic acid (H2CO3) and its conjugate base
bicarbonate ion (HCO3
-).
– The Henderson-Hasselbalch equation for this cconjugate be:
• pH = pKa + log [HCO3
-]/[H2CO3].
– However, ~99 parts of 100 molecules of H2CO3 in aqueous
solution are formed from CO2 dissolved in water:
• The rxn take place in RBCs catalyzed by carbnonic
anhydrase.
• Therefore, in the blood, [CO2] is approximately equal to
[H2CO3].
• Thus The Henderson-Hasselbalch equation can be rewritten
as:
• pH = pKa + log [HCO3
-]/[CO2].
• From this equation, we can deduce; In body fluids, pH
increases with the increase in [HCO3
-] but decreases as
[CO2] increases.
65
66. • The bicarbonate buffer system cont’d…
– The bicarbonate buffer is rather a weak buffer system in
the blood because:
• pKa of H2CO3 w/c is 6.1 is relatively far from 7.4.
• In addition [CO2] & [HCO3
-] in the blood are low or
limited.
– However, this buffer system works in association with the
• respiratory system where by the lungs regulate the
[CO2] and
• the kidney which regulates the [HCO3
-] making the
bicarbonate buffer an important system in the blood
plasma.
66
67. • Phosphate buffer system:
– It involves the dissociation of phosphoric acid which has
three ionizable hydrogen atoms:
• H3PO4 ↔ H+ + H2PO4
- pKa = 2.0
• H2PO4
- ↔ H+ + HPO4
2- pKa = 6.8
• HPO4
2- ↔ H+ + PO4
3- pKa = 12.7
– The second ionization reaction is an important buffer in the
blood b/se 6.8 is close to 7.4. It is the actual phosphate
buffer in the blood.
– Phosphate buffer is primarily important intracellularly
particularly in kidneys where their concentration is high.
– This buffer could have been more efficient than HCO3
-
buffer since its pKa (6.8) is nearer to 7.4 than that of
HCO3
- buffer (pKa = 6.1).
– However, due to low phosphates in plasma, it contributes
to only ~1% of plasma buffering capacity.
67
68. • Amino acid and protein buffers:
– Amino acids have buffering capacity b/se of the
ionizable groups such as the α-COOH, α-NH2 groups
and R-groups. However;
– pKa values of these groups in most amino acids are
far from 7.4 and are not good buffers in the blood.
– Among the amino acids histidine is the most effective
that helps proteins to work as buffers.
– This is because
• The pKa of its imidazole side chain is 6.0 w/c is
relatively nearer to 7.4 and
• It is negatively charged at physiological pH and
acts as a base when histidine is in proteins.
68
69. • Proteins as a buffer:
– Hemoglobin has high number of histidine
residues and accounts for about 60% of
buffering capacity of whole blood.
– Other intracellular and extracellular proteins
(plasma proteins such as albumin) also has
buffering capacity.
– Protein buffer in general contributes about 4%
of the plasma buffering capacity.
69
71. • Acid-Base Imbalances
– Human cells are designed
to function at a narrow
range of pH around 7.4
(N.V. = 7.35 – 7.45)
– Any drastic changes in the
pH can result in
disturbances in the normal
metabolic homeostasis &
life is not possible below
the blood pH of 7.0 or
above the pH of 7.6
– A decrease in the plasma
pH is known as ‘acidemia’
or ‘acidosis’ & the
increase as ‘alkalemia’ or
‘alkalosis’
– Acid-base imbalance can
be classified as:
• Respiratory or
• Metabolic
71
72. • Acid-Base Imbalances cont’d…
– Metabolic acidosis:
• Is a decrease in the alkali (HCO3
-) reserve of the
body
– Respiratory acidosis:
• Accumulation of CO2 due to failure to eliminate it
from the body.
– Metabolic alkalosis:
• Net gain of HCO3
- due to loss of fixed acids such
as HCl from the extra cellular fluids.
– Respiratory alkalosis:
• A decrease in pCO2 due to causes that lead to
alveolar hyperventilation.
72
