metabolism Flashcards
Metabolic reactions: consumed nutrients ->______ -> body’s growth, repair, and normal functioning
chemical
energy and raw materials
sum of all body chemical reactions
metabolism
Exergonic
provide more energy than they consume (Catabolism)
Provides energy and raw materials for
Endergonic
consume more energy than they produce (anabolism)
Growth and Repair
A ____ is a “food or liquid that supplies the body’s
metabolic needs”.
nutrient
Nutrients include:
Necessary chemical, Fuel for energy, Building block or raw material
Water, Minerals(inorganic), Vitamins (organic)
Necessary chemical
Carbohydrates, Lipids, (Proteins)
Fuel for energy
Carbohydrates, Lipids, (proteins)
Building block or raw material
_____ create/use energy in the “high-energy” phosphate bonds of ATP, where it can be released quickly and easily
Cellular reactions
______ temporarily stores and transfers energy given off in catabolic
reactions and transfers it to anabolic reactions that require energy
ATP
Chemical reactions in which a pair of electrons are exchanged
REDOX Reactions
removal (Loss) of electrons
oxidation
addition (Gain) of electrons
Reduction
Oxygen REALLY attracts
______
Reducing oxygen (and oxidizing
something else) gives energy
electrons.
Biological REDOX reactions often move hydrogen ions
along with the electrons and so are called
dehydrogenation (REDOX ) reaction
The electrons/hydrogen are
transferred to _____
NAD, or FAD (B vitamins)
intermediaries
is the body’s preferred source of fuel
glucose
4 ATP: substrate level phosphorylation (directly
transferring a high energy phosphate from one organic
molecule to another) in
glycolysis and the Krebs cycle
either 32 or 34 ATP: xxxxx using the
cytochromes of the electron transport chain
oxidative phosphorylation
(polysaccharide consisting of branched glucose
monomers) is the only stored form of carbohydrate in our
bodies
glycogen
: producing glycogen from glucose
glycogenesis
the opposite of glycogenesis:
stored glycogen is broken down into glucose and released
into the blood to be transported to cells
glycogenolysis
forming “new” glucose (or other steps
in glycolysis/Krebs cycle) from fat or protein (non-
carbohydrate sources)
gluconeogenesis
Chemical reactions are
_____ (ie
Pyruvic acid can be converted
back to glucose
at the cost of ATP)
reversible
one subgroup of lipids called fats
triglycerides
Other lipids include waxes, sterols (steroid hormones), fat-
soluble vitamins (such as vitamins A, D, E and K),
monoglycerides, diglycerides, phospholipids, and others,
Triglycerides are a condensed form of useable energy
read
All single carbon-carbon
bonds
saturated
some double or triple
C-C bonds
unsaturated
nonpolar therefore very hydrophobic
To be transported in watery blood, they combine with lipoproteins (produced in the liver)
Triglycerides
hydrophillic shell
(amphipathic molecules)
hydrophobic interior
lipoproteins
any of a group of soluble proteins that combine with and transport fat or other lipids in the blood plasma.
lipoprotein
fat synthesis
lipogenesis
oxidation
(catabolism) of lipids to yield glucose (which then yields
ATP) the breakdown of fats and other lipids by hydrolysis to release fatty acids.
lipolysis
If the body has no
immediate needs,
lipids are stored
in adipose
tissue
read
Triglyceride->fatty acids +glycerol
lipolysis
fatty acid->
Acetyl-CoA +[H2] +
2shorter fatty acid
Beta oxidation:
the process by which fatty acids are broken down to produce energy
beta oxidation
High levels of Acetyl-CoA from
Beta oxidation in the liver results
in the formation of
ketoacids
is a
normal part of fat breakdown, but
an excess will cause a metabolic
acidosis
Excess ketones can be eliminated
by the kidneys
ketogenesis
are not a primary source of energy; and unlike
lipids and sugars, xxx are not stored
proteins
‘old’ Proteins are broken
down into ____.
“new” amino acids require
_____ (-NH2) _____
amino acids. amino group
transfer of an amino group (NH2) to pyruvic
acid or another acid in the Krebs cycle to form an amino acid
Transamination
removal of an amino group leaving the carbons
of a carboxylic acid to be used to make ATP
Deamination
amino acids that can’t be synthesized
by the body
Essential amino acids:
are the others that can be
synthesized by the body (with an amino group + carbs/lipids
Non-essential amino acids:
acetyl-CoA, glucose-6-phosphate, and
pyruvic acid key entry points into, and out of the
Krebs cycle
pivitol molecules
ingested nutrients are entering the blood
stream from the digestive tract
Storage is important
absorbitive state
energy needs must be met by fuels in the body
Postabsorptive state:
is critical because
the nervous system and red blood cells depend solely on
glucose as an energy source
Maintaining a steady blood glucose
Excess fuel molecules
are converted and _____
in hepatocytes, adipocytes,
and skeletal muscle cells
stored
promotes entry
of glucose and amino acids into
cells
insulin
About 4 hours after the last meal the body works to maintain
normal blood glucose levels
breakdown of liver glycogen, lipolysis, and gluconeogenesis
using lactic acid and amino acids
Every time energy is used or produced in the body some of it
takes the form of
heat
Internal (core) body temperature at 37°C (97-99°F)
read
Heat _____ occurs through:
Metabolism: physical activity in addition to BMR
Basal metabolic rate (BMR) is measured with the body in a
quiet, fasting condition
gain
Heat ____ occurs through:
Evaporation: converting a liquid to a gas (sweat,
moisture from respiratory tract)
loss
Heat _____ (from hot to cold) occurs through:
Conduction: materials in contact with the body
Convection: gas or liquid flows over an object
Thermal radiation: electromagnetic radiation
(infrared, and encompassing visible light) between two
bodies not in contact
(skin and lungs primarily)
transfer
the bodys thermostat
hypothalamus
skin blood vessels constrict
thyroid hormones and catecholamines
(epinephrine and norepinephrine) raise
metabolism.
shivering may ensue
Behavior: You ‘feel cold’
core temperature declines,
blood vessels of the skin dilate
sweat glands are stimulated
metabolic rate is lowered
Behavior: You ‘feel hot’
core temperature rises
