Biochem Exam 1: Set 1 (Eating/Fasting, Collagen, Amino Acids) Flashcards
normal blood glucose levels
80-100 mg/dL (4.4-5.6mM)
This tissue can ONLY use glucose for energy
red blood cells
Amount of energy provided by carbohydrates
4kcal/gm
Amount of energy provided by lipids
9kcal/gm
Amount of energy provided by protein
4kcal/gm
Amount of energy provided by ethanol
7kcal/gm
Most ethanol is metabolized here
liver
Most energy is stored in the form of ___
adipose tissue
Name the essential carbohydrates
There are no essential carbohydrates
Carbohydrates are stored in the form of ____ which is found where in the body?
Glycogen
Found in: muscle tissue, liver, kidney
Body glycogen stores can provide energy for how long?
~24 hours
White and brown adipose tissues differ in their…
organization, location, # of mitochondria, vascularity, and function
Adipose tissue stores fat in the form of…
an intracellular droplet of insoluable triacylglycerols
_____ frees fatty acids by hydrolyzing triglyceride
hormone-sensitive lipase
What is the structure of linolenic acid?
18:3D9,12,15
What is the structure of linoleic acid?
18:2D9,12
What is the structure of stearic acid?
18:0
What is the structure of palmitic acid?
16:0
Protein is stored in the form of…
No storage form of protein
A negative nitrogen balance is indicative of…
a serious infection or starvation
What are the essential amino acids?
His, Ile, Leu, Lys, Met, Phe, Thr, Trp, Val
An individual’s energy requirement is calculated by:
Energy Requirement= BMR x activity level x stress factor
Respiratory Quotient=
RQ= (CO2 produced)/(O2 consumed)
Folate deficiency impairs what?
required for purine synthesis, deficiency impairs cell division/growth, presents as neural tube defects
What is scurvy?
vitamin C deficiency- connective tissue weakness
What is the medical term for starvation and how is it treated?
Marasmus, initially treat with a diet of skim milk and vegetable oil
What is Kwashiorkor syndrome?
protein deficiency but total calories are ok
BMI has units of ___
kg/m^2
An overweight patient has a BMI of ____, and an obese patient has a BMI of ____
overweight: 25-29
obese: 30
What organ will break down glycogen and release glucose into the blood during initial fasting?
liver
Insulin is released by the…
pancreas
What determines a protein’s structure?
amino acid sequence
Explain marginal stability of proteins
easily denatured by changes in temperature, pH, and ionic strength
Phosphorylation typically targets which amino acids?
Ser, Thr, Tyr
Acetylation typically targets which amino acids?
Lys
How does HbA1c differ from other forms of hemoglobin?
HbA1c is glycosylated on the N-terminus of the beta chain
Where does glycosylation of secreted proteins occur?
golgi apparatus
What is the average life time of a red blood cell?
~120 days
Heme iron in hemoglobin is in what state when it is bound by oxygen?
Fe2+
A sigmoidal curve on a plot of substrate saturation vs. substrate concentration is indicative of what?
cooperative binding (ex. hemoglobin)
Oxygenated hemoglobin is in what state?
R state (relaxed)
What is the basic structural unit of collagen
tropocollagen
Which two amino acids are necessary for the left hand triple helix of collagen?
proline- structurally rigid
glycine- every 3rd residue, amide of hydrogen H bonds to carbonyl oxygen of different side chains
Vitamin C is required for what stabilizing reaction in collagen?
conversion of proline to 4-hydroxyproline
How does copper deficiency weaken collagen?
Lysyl oxidase (copper dependent enzyme) converts Lys to allysine, which spontaneously forms aldol cross links
Where does lysyl oxidase form crosslinks in collagen?
Extracellularly
Osteogenesis Imperfecta and Ehlers-Danlos syndrome are both genetic disorders that effect…
collagen
How can low exposure to sunlight cause weak bones?
UV light synthesizes conversion from cholesterol into Vitamin D. Calcium can also increase vitamin D synthesis. Without sunlight Ca resorption from bones to increase vitamin D.
