NYCC Biochemistry II Final I: Fatty Acid Synthesis and Storage, Cholesterol Synthesis Flashcards

Terms Definitions
In which 4 sites does de novo synthesis of fatty acids occur? What is the main organ?
Liver (main organ), Kidney, Mammary gland, Adipose tissue
De novo synthesis of fatty acids occurs from excess intake of _____.
Carbohydrates
Fatty acid synthesis is a(n) ___ stage process that requires the enzymes _____ _____ _____ and _____ _____ _____ _____.
2; Acetyl CoA carboxylase; Fatty acid synthase
Fatty acid synthesis occurs in the _____ via the _____ _____.
Cytosol (cytoplasm); Malate shuttle
In the malate shuttle, _____ _____ from the _____ enters the cytoplasm via the _____-_____ _____.
Acetyl CoA, Mitochondria; Malate-citrate antiporter
The malate shuttle requires _____ from the _____ _____ _____.
NADPH; Pentose phosphate shunt
In the malate shuttle, _____ is also supplied via _____ _____ _____ _____.
NADPH; NADP dependent malate dehydrogenase (malic enzyme)
Acetyl CoA production in the cytoplasm requires the enzyme _____ _____ _____.
ATP citrate lyase
Acetyl CoA production in the cytoplasm has the formula:
_____-> _____ + Acetyl CoA
Citrate; OAA

(Enzyme: ATP citrate lyase)
Stage 1 of the malate shuttle requires the enzyme _____ _____ _____ and the coenzymes _____ and _____.
Acetyl CoA carboxylase; Biotin; ATP
Stage 1 of the malate shuttle has the formula:
_____ ______ + ______ -> ______ ______
Acetyl CoA + CO2 -> Malonyl CoA
In stage 1 of the malate shuttle, formation of carboxy-biotin also requires _____.
ATP
_____ of Acetyl CoA carboxylase:
1. Requires citrate to make active polymer
2. Requires insulin
3. Up-regulated by a high carbohydrate/low fat diet
Activation
Activation of Acetyl CoA carboxylase:
1. Requires _____ to make active polymer
2. Requires _____
3. Up-regulated by a ______ _____ or _____ _____ diet
Citrate; Insulin; High carbohydrate or Low fat
_____ of Acetyl CoA carboxylase:
1. Palmitoyl CoA inhibits polymer activation
2. Glucagon and epinephrine
3. Down-regulation by high fat/low carbohydrate diet
a. Ketogenic diet: decreases fatty acid synthesis but increases cholesterol synthesis (LDL)
Inhibition
Inhibition of Acetyl CoA carboxylase:
1. _____ _____ inhibits polymer activation
2. ______ and _____
3. Down-regulation by _____ _____ or _____ _____ diet
a. _____ diet: decreases _____ _____ synthesis but increases _____ synthesis
Palmitoyl CoA; Glucagon and Epinephrine; High fat or Low carbohydrate; Ketogenic; Fatty acid; Cholesterol (LDL)
Stage 2 of the malate shuttle requires the enzyme _____ _____ _____.
Fatty acid synthase
Fatty acid synthase (Malate shuttle stage 2):
1. _____-_____ _____
2. ___ _____ enzyme activities
3. _____ _____ protein
4. _____ of identical _____ arranged _____ to _____.
Multi-enzyme complex; 7 distinct; Acyl carrier; Dimer; Polypeptide; Head to tail
Requirements for synthesis of one molecule of Palmitate:
1. 8 molecules of _____ _____
a. _____ _____ + 7 _____ ______
b. Releases 7 _____
2. 7 _____
3. 14 _____
a. Releases _____ + 7 _____
Acetyl CoA; Acetyl CoA; Malonyl CoA; CO2; ATP; NADPH; Water; ADP
______ of fatty acid synthase is caused by a high carbohydrate and low fat diet.
Activation
_____ of fatty acid synthase is caused by high levels of circulating free fatty acids (FFA).
Inhibition
______ is the source of long-chain fatty acids except EFA.
Palmitate
Fatty acid elongation:
1. Occurs in the _____.
2. Enzyme: Multi-enzyme complex _____ _____ _____
3. Substrate: _____ _____
4. Coenzyme: _____
SER; Fatty acid elongase; Malonyl CoA; NADPH
Production of medium and short chain fatty acids:
1. Location: _____
2. Process: Reverse of _____-_____
3. Enzymes: _____ dependent
4. Substrate: _____ _____
Mitochondrion; Beta-oxidation; NADH; Acetyl CoA
Production of very long chain fatty acids (22-24 C):
1. Location: _____
2. Substrate: Elongation of _____ _____
3. Required for: synthesis of _____ during _____
Brain; Stearoyl CoA; Sphingolipids; Myelination
Desaturation of non-essential fatty acids:
1. Bond can only be added at _____ ___
Palmitic -> _____
Stearic -> _____
2. Enzyme: _____ ___ _____
Delta 9; Palmitoleic; Oleic; Delta 9 Desaturase
Essential Fatty Acids:
1. _____ (18:2) (omega 6)
2. _____ _____ (18:3) (omega 3)
3. _____ _____ (18:3) (omega 6)
Linoleic; Alpha linolenic; Gamma linolenic
Essential Fatty Acids:
1. Linoleic (18:___) (omega ___)
2. Alpha linolenic (18:___) (omega ___)
3. Gamma linolenic (18:___) (omega ___)
1. 2; 6
2. 3; 2
3. 3; 6
What are the food source(s) and deficiency symptoms of linoleic acid?
Food sources: corn, soybean, peanut oil
Deficiency: Eczema or bumps on back of arms
What are the food source(s) and deficiency symptoms of alpha linoleic acid?
Food sources: Flax seed (linseed), black currant seed oil
Deficiency: trouble concentrating, heart disease, and cancers
What are the food source(s) of gamma linoleic acid?
Food source: Evening primrose oil
Humans are unable to make _____ ______ _____ and so must consume them.
Essential fatty acids
_____ essential fatty acids:
1. Linoleic acid -> Arachidonic acid
a. Delta 6 desaturase and elongase
2. Linolenic acid -> EPA (eicosapentaenoic acid) -> DHA (docosahexaenoic acid)
a. Delta 6 desaturase and elongase
Conditionally
Conditionally essential fatty acids:
1. Linoleic acid -> _____ acid
a. _____ ___ _____ and _____
2. Linolenic acid -> _____ (_____acid) -> _____ (_____ acid)
a. _____ ___ _____ and _____
Arachidonic; Delta 6 desaturase; Elongase; EPA; Eicosapentaenoic; DHA; Docosahexaenoic; Delta 6 desaturase; Elongase
Fatty acids are stored as _____, also known as _____.
Triacylglycerol; Trigylcerides
Glycerol 3P (required for storage of fatty acids) sources:
1. _____ via _____ _____ in _____
2. _____ from _____ in _____
1. Glycerol; Glycerol kinase; Liver
2. DHAP; Glycolysis; Adipose
Regulation of total body fat stores:
1. Number and size of _____
2. _____ linked factors
a. _____ receptors
3. _____
Adipocytes; Genetically; Dopamine; Leptin
Regulation of total body fat stores (environmental factors that increase caloric intake):
1. Eating a _____ _____ of food
2. Eating with _____ _____
3. Availability of _____ _____ foods
Wide variety; More people; Energy dense
Leptin:
1. _____ _____ _____ protein
2. Produced by _____ _____ _____
3. Metabolic target: _____
4. Effect: _____ of food intake via _____ _____ hormone (CRH) and _____ of _____ ___
Small molecular weight; White adipose tissue; Hypothalamus; Suppression; Corticotrophin releasing; Suppression; Neuropeptide Y
_____ functions:
1. Component of mammalian cell membranes
2. Precursor of:
Bile acids
Steroid hormones
Vitamin D
Cholesterol
Cholesterol functions:
1. Component of mammalian _____ _____
2. Precursor of:
_____ _____
_____ _____
_____ ___
Cell membranes; Bile acids; Steroid hormones; Vitamin D
Disorders of _____ metabolism:
1. Cardiovascular disease
2. Gall stones
Cholesterol
Disorders of cholesterol metabolism:
1. _____ disease
2. _____ _____
Cardiovascular; Gall stones
Sources of cholesterol in the body:
1. 50% synthesized in the _____ of the _____
2. 50% from ____
a. Only _____ sources (_____, _____, _____)
b. Typical Western diet contains ___ mg/day
Cells of the body; Diet; Animal; Eggs, meat, milk; 500
Sites of cholesterol synthesis:
1. _____ (primary)
2. _____, _____, _____ (secondary)
1. Liver
2. Intestine, adrenal cortex and gonads
Energetic cost of cholesterol production:
1. ___ moles of _____ _____
2. ___ moles of _____
3. ___ moles of _____
1. 18; Acetyl CoA
2. 36; ATP
3. 16; NADPH
Stages of cholesterol synthesis :
1. _____ _____-> HMG-CoA -> _____
2. _____forms active _____ units (_____ _____)
3. ___ molecules of _____ _____ -> _____
4. _____ -> _____
5. _____ -> _____
1. Acetyl CoA; Mevalonate
2. Mevalonate; Isoprenoid; Farnesyl pyrophosphate
3. 2; Farnesyl pyrophosphate; Squalene
4. Squalene ; Lanosterol
5. Lanosterol; Cholesterol
Cholesterol synthesis (stage 1):
Acetyl-CoA -> acetoacetyl-CoA -> HMG-CoA -> Mevalonate
1. Occurs in the _____
2. Regulatory enzyme: _____-_____ _____
3. Coenzymes: _____
Cytosol; HMG-CoA Reductase; NADPH
Cholesterol synthesis (stage 2):
Mevalonate forms active isoprenoid units (farnesyl pyrophosphate)
1. Enzymes: _____ and _____
2. Coenzymes: _____ and ____
Kinase; Decarboxylase; ATP and Magnesium
The final isoprenoid unit, farnesyl pyrophosphate, is a precursor to form _____ (_____ ___).
Ubiquinone; Coenzyme Q10
Cholesterol synthesis (stage 3): Condensation of two molecules of farnesyl pyrophosphate forms squalene (a linear molecule capable of folding into a _____)
1. Enzyme: _____ _____
2. Found in _____ _____
3. Coenzymes: _____, _____, _____
Ring; Squalene synthase; Endoplasmic reticulum; NADPH, Mg, Mn
Cholesterol synthesis (stage 4):
Squalene -> Lanosterol
1. Enzyme: _____
Cyclase
Cholesterol synthesis (stage 5):
Lanosterol -> Cholesterol
1. Occurs while bound to a _____ and _____-binding protein
Via loss of three _____ and _____
2. Enzymes: _____
3. Coenzyme: _____
1. Squalene; Sterol; Decarboxylations and reductases
2. Reductase
3. NADPH
Cholesterol has ___ carbons with an _____ group.
27; -OH
Cholesterol is _____ _____ _____ by regulation of HMG-CoA.
End product inhibited
Regulation of HMG-CoA Reductase (_____ enzyme):
1. Inhibition of Activity:
a. _____ and _____
b. Increased concentration of _____
2. Increased Activity:
a. _____ and _____ _____
b. _____ is the primary hormone that increases the activity
Allosteric
1. Glucagon; Cortisol (glucocorticoids); Cholesterol
2. Insulin and Thyroid hormones (T3); Insulin
Attempts to lower cholesterol by decreasing _____ _____ in humans have varying results.
Dietary intake
Cholesterol intake in rats:
1. 0.05% dietary cholesterol causes ___-___% of body cholesterol to be _____
2. 2% dietary cholesterol decreases _____ to ___%
70-80; Synthesized; Synthesis; 50
Lifestyle traits that elevate blood cholesterol levels:
_____blood pressure, _____, _____ gender, _____ obesity, Lack of _____, Drinking _____ water, Elevated serum _____ _____ _____
High; Smoking; Male; Abdominal; Exercise; Soft; Free fatty acids
Lifestyle traits that elevate FFAs:
Emotional _____, _____ _____, _____ drinking, _____ _____ meals rather than _____ _____ meals
Stress; Cigarette smoking; Coffee; Few large; Many small
Drugs classes that lower cholesterol:
1. _____ drugs
a. inhibit ____-____ _____
2. Examples
a. _____
b. _____
c. _____
Statin; HMG-CoA Reductase; Lipitor; Zocor; Provochol
Statin cholesterol drugs inhibit the synthesis of _____ _____, so supplementation of _____ mg/day is recommended.
Coenzyme Q10, 100
_____ _____ are synthesized in the _____ from cholesterol and, quantitatively, are the most important metabolic product of cholesterol.
Bile acids, Liver
_____ _____ characteristics:
1. Cholic and Chenodeoxycholic
2. Regulatory Enzyme:
Microsomal 7 alpha hydroxylase
Coenzymes: NADPH, O2, cytochrome P450 and Vitamin C
Bile acid
Bile acid characteristics:
1. _____ and _____
2. Regulatory Enzyme:
_____ ___ _____ _____
3. Coenzymes: _____, _____, _____ _____, and _____ ___
1. Cholic; Chenodeoxycholic
2. Microsomal 7 alpha hydroxylase
3. NADPH, O2, Cytochrome P450 and Vitamin C
_____ _____ types:
1. Primary (Liver)
a. Glycocholic acid
b. Glycochenodeoxycholic acid
c. Taurocholic acid
d. Taurochenodeoxycholic acid
2. Secondary (Intestine)
a. Deoxycholic acid
b. Lithocholic acid
Bile acid
Bile acid types:
1. _____ (_____)
a. Glycocholic acid
b. Glycochenodeoxycholic acid
c. Taurocholic acid
d. Taurochenodeoxycholic acid
2. _____ (_____)
a. Deoxycholic acid
b. Lithocholic acid
Primary (Liver); Secondary (Intestine)
Functions of _____ _____:
1. Assist the digestion of dietary fat
a. acts as an emulsifier which aids enzymatic digestion and therefore absorption
2. Secretion of bile is hormone controlled
a. hepatocrinin secretes bile from the liver
b. cholecystokinin
Bile acids
Functions of bile acids:
1. Assist the digestion of dietary _____
a. acts as an _____ which aids _____digestion and therefore _____
2. Secretion of bile is _____ controlled
a. _____ secretes bile from the _____
b. _____ causes emptying of the bile duct
1. Fat; Emulsifier; Enzymatic; Absorption
2. Hormone; Hepatocrinin; Liver; Cholecystokinin (CCK); Duodenum
Reabsorption of bile acids:
1. ___g of bile acids pass into the _____ per day
2. ___% of bile acids/salts are _____
a. Enter the _____ (_____) circulation [not systemic]
b. Re-secreted into _____
1. 30; Intestines
2. 98; reabsorbed
a. Enterohepatic (Portal)
b. Bile
Cholesterol metabolism and excretion:
1. Cholesterol cannot be digested or broken down to _____ _____ and _____
2. Removal is dependent on transfer into the _____ to be excreted in the _____
3. ___ gram(s) cholesterol is eliminated in the feces
a. 50% as
1. Carbon dioxide; Water
2. Gut; Feces
3. 1; Bile acids; Cholesterol; Bacteria; Coprostanol
In guinea pigs, _____ ___ deficiency leads to cholesterol accumulation and atherosclerosis.
Vitamin C
Bile acids (vitamin C deficiency mechanism):
1. Decreased activity of ___ _____ _____
a. Leads to decreased _____ _____ production
b. Leads to decreased excretion of _____
1. 7 alpha hydroxylase
a. Bile acid
b. Cholesterol
Natural remedies that lower cholesterol:
1. _____ ___
a. allows cholesterol to be converted to _____ _____ and secreted into the _____.
2. _____(especially _____ _____)
a. Binds _____ and _____ _____ and excretes them in the feces
b. Reason that _____
1. Vitamin C; Bile acids; Intestines
2. Bran; Oat bran
a. Cholesterol; Bile acids
b. Oat cereals
Synthesis of _____ _____:
1. Cholesterol -> Progesterone
a. Progesterone -> Cortisol
b. Progesterone -> Androstenedione -> Testosterone
i. Testosterone -> Dihydrotestosterone
3. Testosterone -> Estradiol
Steroid hormones
Synthesis of steroid hormones:
1. Cholesterol -> Progesterone
a. Progesterone -> _____
b. Progesterone -> Androstenedione -> Testosterone
i. Testosterone -> ______
3. Testosterone -> _____
Cortisol; Dihydrotestosterone; Estradiol
Alternate Route of _____ _____ synthesis (Via DHEA):
1. Cholesterol -> Pregnenalone -> DHEA -> Androstenedione:
a. -> _____
b. -> _____
Steroid hormone; Testosterone; Estrone
/ 77
Term:
Definition:
Definition:

Leave a Comment ({[ getComments().length ]})

Comments ({[ getComments().length ]})

{[comment.username]}

{[ comment.comment ]}

View All {[ getComments().length ]} Comments
Ask a homework question - tutors are online