Transcript Metabolism - UCO

Metabolism
Biology 1114
Energy
•
•
•
•
•
Capacity to Do Work
Calories / Joules
1 calorie = 4.184 Joules
Biologists Use Calories
Physicists and Chemists Use Joules
Cells Require Energy
• Phototrophs
• Chemolithotrophs
• Chemoorganotrophs
• Activation Energy is the additional energy
required for a particular process to occur
Metabolism is the Sum Total of all the
Chemical Reactions Within a Living
Organism.
Anabolism
•
•
•
•
•
Make New Molecules
Simple to Complex
Assimilative
Biosynthetic
Endergonic
Metabolism is the Sum Total of all the
Chemical Reactions Within a Living
Organism.
Catabolism
•
•
•
•
•
Used to Obtain Energy
Complex to Simple
Degradative
Dissimulative
Exergonic
The Earth’s Energy Comes From the Sun
ATP
The universal energy carrying
molecule in living organisms.
• 1 Adenine
• 3 Phosphates
• Ribose
The terminal 3rd Phosphate bond is a special high-energy bond.
Function of Mitochondria
• Glucose Enters Mitochondria which is filled with
ADP
• Glucose Bonds are Broken and Energy is Released
• This Energy is Used to Add the Third Phosphate to
ADP
• This Process is Phosphorylation
• ATP Travels to Wherever Energy is Needed
• Third Phosphate is Cleaved and Energy is
Released
• ADP Returns to Mitochondria
• Process Begins Again
Phosphorylation
The Principle
of Molecular
Recognition
•
•
•
•
Living Organisms are Very Complicated
High Level of Regulation is Necessary
Regulation is Achieved Through Recognition
Recognition Causes a Preprogrammed Response
Sound Stimuli/Recognition Leads to Response
Visual Stimuli/Recognition Leads to Response
The Principle of Molecular
Recognition
• Specialized Cells
• Binding by Ligands to
Receptors
• Message Transfer to
the Cell’s Interior
• Control Center
Initiates a Response
Metabolic Pathways
Energy is passed from one molecule to another via metabolic
pathways
• Definition
– An ordered series of chemical reactions
• Mediated by Enzymes
– Proteins that catalyze chemical reactions by lowering
activation energy
– Large proteins with a characteristic three dimensional shape
• The Tools of Life
– Have one specific job to do and are very efficient
– Operate at normal to low temperatures
– Catalysts that can be reused again and again
Enzymes catalyze chemical reactions by lowering the activation
energy required for the reaction to occur.
So How Might a
Diet Pill Work?
What is the problem
with this?
Enzymes
•
•
•
•
•
•
•
End in ASE
Named by Substrate or Chemical Reaction
Proteases
Lipases
DNAses
Lactase
Glucokinase
There are six classes of enzymes and these are
defined on the basis of the type of reaction they
catalyze
Enzyme Components
Enzyme Characteristics
•
•
•
•
•
•
Organic Catalysts
Renewable
Large
Work Quickly
Stable and Long Lasting
Unique Functional Structure
Lock and Key Paradigm
1. Interaction Between Enzyme and Substrate
2. Initiates a Preprogrammed Reaction
3. Causes Substrate Transformation
Denaturation
• 12:50 2001-02-27
• Child survives after being dead for 90 minutes
•
A 13-month-old female toddler who had wandered out
through an open kitchen door, was found lying face-down
in the snow, in temperatures of about minus 4 degrees
Fahrenheit (minus 20 Celsius) on Saturday. She was
wearing only a diaper. Her heart stopped beating for more
than 90 minutes, but she suffered no brain damage and is
now recovering in the Edmonton hospital where she was
treated for extreme hypothermia. Police, who declined to
give her name, believe she may have become disoriented
after leaving the bed in which she has been asleep with her
mother. The 26-year-old mother, who had gone to bed
around 10 p.m., awoke about 3 a.m., found the toddler
missing, and began a frantic search.
• Outside, she followed the child's footprints and
found her lying frozen in the snow. Paramedics,
who arrived after a 911 emergency call, found she
had no pulse. At the University of Alberta
Hospital, doctors put her in a "bear hug" blanket to
circulate warm air around her body and raise her
body temperature, but normal medical procedures
failed to get her heart beating again. Doctors were
about to begin surgery to put her on a heart-lung
machine when, just before 5 a.m., they were
astonished to find the baby's heart began beating
again on its own. There have been four or five
other documented cases of very small children
surviving after been frozen in sub-zero weather
conditions, doctors are quoted by UPI as saying.
• On May 30, 2002, a 30-year old landscape
mowing assistant collapsed and died at the end of
a day of caring for residential lawns. A typical
day’s work consisted of mowing, edging,
trimming with a weed whip, and finishing with a
back-pack blower. His partner, the leader of the
two-man crew, witnessed his collapse and
immediately called for help. Emergency medical
assistance responded and he was transported to the
hospital where he was pronounced dead. At the
hospital, a rectal temperature of 107.6 degrees
Fahrenheit was recorded.
Factors Influencing Enzymatic Activity
1. Temperature
2. pH
3. Concentration
Inhibition
Example of Feedback Inhibition
In the brain there exists an important
system-wide regulatory center known as
the hypothalamus. The hypothalamus
synthesizes and releases a hormone called
thyrotropin-releasing-hormone (or TRH).
The release of TRH by the hypothalamus
causes release of thyrotropin-stimulatinghormone (or TSH) by the nearby pituitary
gland. TSH from the pituitary travels via
circulation to the thyroid tissues and is the
most significant factor for stimulating the
synthesis and release of biologically active
thyroid hormone molecules. The
hypothalamus is also sensitive to levels of
TSH; when TSH levels are increased, there
is feedback of this information to the
hypothalamus resulting in the cessation of
further synthesis and release of more TRH