Download 17-1 Checkpoint - Jordan High School

Chapter 17
Metabolism & Energetics
17-1: Metabolism
 Chemical
reactions within mitochondria
provide cells with energy
 Supports
growth, cell division, etc.
 Metabolism—all
the chemical reactions
that occur in the body
 Relies
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on amino acids, lipids, & simple sugars
 Catabolism—breakdown
molecules
 Releases
energy for use in making ATP
 Anabolism—formation
molecules
 Forms
of organic
of new organic
new chemical bonds
 Requires energy formed from catabolic
reactions
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 Reasons
for making new compounds:
 Performing
body repairs
 Support growth
 Produce secretions
 Build nutrient reserves (store nutrients)
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17-1 Checkpoint
1.
Define metabolism.
2.
Compare catabolism and anabolism.
3.
Explain why cells need to make new
compounds.
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17-2: Carbohydrate
Metabolism
 Most
ATP is generated by breaking down
carbohydrates, inside mitochondria
 Anaerobic
reactions don’t require oxygen;
aerobic reactions require oxygen
 Cellular
respiration—responsible for ATP
production
 Glycolysis,
chain
citric acid cycle, electron transport
Glycolysis
 Glycolysis—breakdown
of 6-carbon
glucose to two 3-carbon pyruvate
molecules
 Occurs
 Uses
in the cell cytosol
2 ATP to start process; produces 4
ATP (net gain of 2)
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 Glycolysis
steps:
 Glucose
enters cell
 2 ATP break down to 2 ADP, release 2 P
 Glucose molecule split to two 3-carbon chains
 Final
products:
2
pyruvate
 2 ATP
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The Citric Acid Cycle
 Citric
acid cycle—pyruvate combines with
a substrate to form ATP
 Occurs
in the outer mitochondria
combines with coenzyme A (CoA)
to form 2-carbon acetyl-CoA
 Pyruvate
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 Citric
acid cycle steps:
 Acetyl-CoA
combines with 4-carbon oxaloacetic
acid to form 6-carbon citric acid
 Rearrangement of molecules produces 2 CO2 &
ATP
 Cycle turns twice (once per pyruvate molecule)
 Final
product: 2 ATP
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The Electron Transport System
 Electron
transport system (ETS)—series
of proteins that generates 95% of ATP
 Occurs
in the inner mitochondria
 Electrons
 Requires
 Final
passed through ETS generate ATP
oxygen
product: 32 ATP
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Energy Yields of Glycolysis &
Cellular Respiration
 From
one molecule of glucose:
 Glycolysis:
2 ATP, 2 pyruvate
 Citric acid cycle: 2 ATP
 Electron transport chain: 32 ATP
 36
ATP total made from 1 glucose molecule
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17-2 Checkpoint
1.
What molecule is needed for glycolysis,
and what is formed upon completion of
glycolysis?
2.
What is the primary role of the citric acid
cycle in the production of ATP?
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17-3: Lipid Metabolism
 Lipolysis—breaking
down lipids
1
lipid molecule can provide 144 ATP
 Glucose metabolized quicker than lipids
 Lipogenesis—formation
 Lipids
of lipids
circulate in bloodstream as
lipoproteins (lipid-protein complexes)
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Cholesterol
 Cholesterol
hormones
composes cell membranes,
 Low-density
lipoproteins (LDLs)—
deliver cholesterol to peripheral tissues

“Bad cholesterol”
 High-density
lipoproteins (HDLs)—
transport excess cholesterol from tissues
 “Good
cholesterol”
 High
cholesterol linked to atherosclerosis,
heart disease
 Genetics,
levels
 Below
lifestyle choices affect cholesterol
200 = OK
 200 – 239 = modify diet
 Above 240 = lifestyle changes
17-3 Checkpoint
1.
Define lipolysis.
2.
Why are high-density lipoproteins (HDLs)
considered beneficial?
3.
What are some benefits with cholesterol?
What are some problems with cholesterol?
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17-4: Protein Metabolism
 Proteins
 More
 Amino
broken down into amino acids
difficult to break down than carbs/lipids
acids combine to form proteins
 Phenylketonuria
(PKU)—disorder in
which phenylalanine can’t be converted to
another amino acid
 Can
damage CNS & brain
 Tests performed after birth
17-4 Checkpoint
1.
How are proteins formed?
2.
Why is phenylketonuria (PKU) a dangerous
disorder if undetected?
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17-6: Nutrition
 Nutrition—absorption
from food
of essential nutrients
 Balanced
diet—contains all the nutrients
needed to maintain homeostasis
 Prevents
malnutrition—inadequate or
excessive intake of nutrients
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Food Groups
 Food
pyramid updated to “MyPlate”
 Color-coded
food groups indicate
proportions of food needed from five basic
food groups
 Grains,
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vegetables, fruits, protein, dairy
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 Nutrients
must be obtained in sufficient
quantity & quality
 Complete
proteins—contain essential
amino acids (beef, fish, poultry, eggs, milk)
 Incomplete
proteins—missing essential
amino acids (plants)
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Minerals & Vitamins
 Minerals—ions
processes
important for body
 Vitamins—organic
nutrients
 Fat-soluble—dissolve
in lipids (A, D, E, K)
 Water-soluble vitamins—easily move
throughout body (B, C)
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17-6 Checkpoint
1.
Identify the two types of vitamins.
2.
What is the difference between foods
described as containing complete proteins
and those described as containing
incomplete proteins?
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17-7: Metabolic Rate
Energy Content of Food
 Calorimeter—device
used to measure
Calorie content of food
 Lipids
= 9.46 Calories/g
 Carbohydrates = 4.18 Calories/g
 Proteins = 4.32 Calories/g
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Metabolic Rate
 Metabolic
rate—sum of all processes
occurring in body
 Increases
with exercise/activity
 Basal
metabolic rate (BMR)—represents
the minimum energy needed by an awake,
resting person
 Influenced
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by age, gender, fitness, genetics
Thermoregulation
 Thermoregulation—processes
body temp within normal ranges
 Mechanisms
that keep
of heat transfer:
 Radiation—heat
lost as infrared radiation
 Conduction—heat lost through contact
 Convection—heat lost as warm air rises
 Evaporation—sweat on skin evaporates & cools
body
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 Heat-loss
centers & heat-gain centers
in brain adjust body temp
 Promoting
 Blood
vessels dilate, sweat glands stimulated
 Promoting
 Blood
heat loss:
heat gain:
vessels constricted, sweat glands
inhibited, shivering begins
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17-7 Checkpoint
1.
Compare a pregnant woman’s BMR to her
BMR when she is not pregnant.
2.
What effect would vasoconstriction of
blood vessels have on a hot day?
3.
Why does shivering promote heat gain in
the body?
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