Intro to metabolism Flashcards
exam 2
Predict the relative caloric needs of
an average 22 year old moderately active male
an average 22 year old male victim of a major burn
3. an average 22 year sedentary male
4. an average 32 year old sedentary female
5. an average 60 year old active female
a. 1>2>3>4>5
b. 1>3>2>4>5
c. 1>3>4>5>2
d. 2>1>3>5>4
e. 2>1>3>4>5
d. 2>1>3>5>4
Where Do Polysaccharides Get Digested?
mouth, intestine, colon
Which of the following describes the action of a-amylase?
A. It cleaves glucose a 1→4 glucose bonds but not glucose a 1→6 glucose bonds. B. It occurs in the brush border membrane of intestinal epithelial cells. C. It digests starch completely to the monosaccharide glucose. D. Its digestion products are all short linear chains of glucose. E. Salivary amylase remains active in the stomach.
A. It cleaves glucose a 1→4 glucose bonds but not glucose a 1→6 glucose bonds.
Active transport of glucose occurs in which tissue:
A. Brain occurs because brain requires glucose as fuel B. Kidney to prevent loss of glucose to the urine C. Liver to help lower blood glucose levels
Muscle to support exercise
E. Red blood cells because they have no mitochondria
B. Kidney to prevent loss of glucose to the urine
Insulin increases the transport of glucose from the blood into:
A. Brain cells
B. Kidney cells
C. Liver cells
D. Muscle cells
E. Red blood cells
D. Muscle cells
fuel is stored as _____ limited
glycogen
fuels is stored as ______ limited but more
protein
fuels is stored as ________ limitless
triglycerides
enzymes that have same function but different structure
isozymes
why is metabolism different in tissues? (3)
(1) carry out different processes
(2) use/produce different fluids
(3) isozymes
synthesis
anabolism
degradation
catabolism
refers to the interconversions of molecules of the metabolome
metabolism
metabolism is controlled by proteins _____, which in turn results from information encoded in DNA and RNA, ______ and _______
controlled by the proteome and encode the genome and transcriptome
lacks glucose-6-phosphatase
muscle
example of isozymes
hexokinase and glucokinase
pathways may be _____ like glycolysis, ______ like TCA, or _______ like fatty acid synthesis
linear, cyclic, or spiral
what is expected to occur at steps that are out of equilibrium?
regulation by altering activities of the enzyme catalyzing those steps.
enzyme regulation can occur by ______ small molecules, _______ post-translational modification, _______ changes in enzyme amount, or _______ compartmentalization
- allosteric regulation
- phosphorylation
- synthesis/degradation
- fatty acid oxidation in mitochondria
Hormones such as ___________ can remodel enzyme activites to alter metabolism
insulin in the well-fade state
caloric intake of fat
9 cal/gram
caloric intake of protein
4 cal/gram
caloric intake of carbohydrate
4 cal/gram
what does the glycemic index of food estimates
its effect on blood glucose and insulin levels
why is cellulose, a polyglucose like amylase is not a useful source of food?
it has beta linkages that our enzymes cannot cleave
in kidney and intestine glucose/galactose transport is
active with a sodium co-trasnport
SGLT1,2
glucose is transported by ______ in most cells
facilitated diffusion
Glut 2 important in
liver
Glut 4 important in
muscle, fat and white cells
Glut 4 is regulated by
insulin leading to increased uptake of glucose
carbohydrates enter portal circulation with the ______ as an initial destination
liver
Causes of malabsorption: (4)
(1) lactase deficiency
(2) transported deficiency
(3) defects in SGLT1
(4) decreased intestinal surface area
does serine syntheis & degradation go on identical paths?
NO!!!!
allosteric inhibition or stimulation by small molecules is
immediate
