Podcast
Questions and Answers
What is the role of diacylglycerol in the biosynthesis of triacylglycerols?
What is the role of diacylglycerol in the biosynthesis of triacylglycerols?
- It is a breakdown product of triacylglycerols.
- It inhibits the activity of lipases.
- It serves as a precursor for various lipid molecules. (correct)
- It is synthesized only in the intestines.
In which tissues does the majority of triacylglycerol biosynthesis occur?
In which tissues does the majority of triacylglycerol biosynthesis occur?
- Muscle and kidney tissues.
- Adipose tissue, liver, and intestines. (correct)
- Brain and heart tissues.
- Skin and lung tissues.
What enzyme is responsible for the conversion of diacylglycerol into triacylglycerol?
What enzyme is responsible for the conversion of diacylglycerol into triacylglycerol?
- Glycerol-3-phosphate dehydrogenase.
- Phospholipase.
- Diacylglycerol acyltransferase. (correct)
- Acyl-CoA synthetase.
How does triacylglycerol produced from dietary intake differ from that synthesized in tissues?
How does triacylglycerol produced from dietary intake differ from that synthesized in tissues?
What is the function of glycerol-3-phosphate dehydrogenase in lipid metabolism?
What is the function of glycerol-3-phosphate dehydrogenase in lipid metabolism?
What is the rate-limiting step in cholesterol biosynthesis?
What is the rate-limiting step in cholesterol biosynthesis?
Which intermediates are produced during the conversion of mevalonate in the cholesterol biosynthesis pathway?
Which intermediates are produced during the conversion of mevalonate in the cholesterol biosynthesis pathway?
What is the final product formed from the cyclization of squalene in cholesterol biosynthesis?
What is the final product formed from the cyclization of squalene in cholesterol biosynthesis?
What is the initial substrate for the synthesis of mevalonate in cholesterol biosynthesis?
What is the initial substrate for the synthesis of mevalonate in cholesterol biosynthesis?
During cholesterol biosynthesis, how many distinct processes are involved in its pathway?
During cholesterol biosynthesis, how many distinct processes are involved in its pathway?
What are lipids primarily classified based on?
What are lipids primarily classified based on?
Which of the following lipids are essential components of membrane structure?
Which of the following lipids are essential components of membrane structure?
What does 'glycolipid' refer to in lipid classification?
What does 'glycolipid' refer to in lipid classification?
Which class of lipids includes sphingomyelins?
Which class of lipids includes sphingomyelins?
What role do lipids generally have in biological membranes?
What role do lipids generally have in biological membranes?
Which of the following is NOT a characteristic of phospholipids?
Which of the following is NOT a characteristic of phospholipids?
Which statement best describes the role of isoprenoids?
Which statement best describes the role of isoprenoids?
Which type of lipid is primarily involved in energy storage?
Which type of lipid is primarily involved in energy storage?
What is the role of ceramide in sphingolipid biology?
What is the role of ceramide in sphingolipid biology?
Which molecule is produced by transferring phosphocholine from phosphatidylcholine?
Which molecule is produced by transferring phosphocholine from phosphatidylcholine?
Which carbohydrate interacts with galactose as indicated in the content?
Which carbohydrate interacts with galactose as indicated in the content?
What type of biological molecule is ceramide classified as?
What type of biological molecule is ceramide classified as?
Which plant condition is suggested for the introduction of a double bond into fatty acyl chains?
Which plant condition is suggested for the introduction of a double bond into fatty acyl chains?
What is the primary configuration of the fatty acyl chain mentioned?
What is the primary configuration of the fatty acyl chain mentioned?
Which of the following describes sphingomyelin?
Which of the following describes sphingomyelin?
Which of the following statements about fatty acyl chains is true?
Which of the following statements about fatty acyl chains is true?
What is the role of CDP-diacylglycerol in eukaryotic cells?
What is the role of CDP-diacylglycerol in eukaryotic cells?
Which of the following is generated from the condensation of palmitoyl-CoA and serine?
Which of the following is generated from the condensation of palmitoyl-CoA and serine?
What function does CMP serve in the activation of CDP-diacylglycerol?
What function does CMP serve in the activation of CDP-diacylglycerol?
What type of molecule is CDP-diacylglycerol classified as?
What type of molecule is CDP-diacylglycerol classified as?
Which phospholipid is NOT derived from CDP-diacylglycerol?
Which phospholipid is NOT derived from CDP-diacylglycerol?
What is the final product of the reduction of β-ketosphinganine?
What is the final product of the reduction of β-ketosphinganine?
Which of the following processes involves the hydrolysis of CDP-diacylglycerol?
Which of the following processes involves the hydrolysis of CDP-diacylglycerol?
Which enzyme is involved in synthesizing β-ketosphinganine?
Which enzyme is involved in synthesizing β-ketosphinganine?
What molecule is produced when glycerol is phosphorylated by glycerokinase?
What molecule is produced when glycerol is phosphorylated by glycerokinase?
Which enzyme catalyzes the reversible formation of phosphatidic acid from diacylglycerol?
Which enzyme catalyzes the reversible formation of phosphatidic acid from diacylglycerol?
In eukaryotic systems, which molecule can be used as a starting point for synthesizing phosphatidic acid?
In eukaryotic systems, which molecule can be used as a starting point for synthesizing phosphatidic acid?
Which of the following statements about phosphatidic acid synthesis is NOT true?
Which of the following statements about phosphatidic acid synthesis is NOT true?
What is the role of acyl-CoA in phosphatidic acid synthesis?
What is the role of acyl-CoA in phosphatidic acid synthesis?
What provides the phosphate group in the formation of phosphatidic acid?
What provides the phosphate group in the formation of phosphatidic acid?
When glycerol-3-phosphate is acylated, which positions are modified?
When glycerol-3-phosphate is acylated, which positions are modified?
What is produced by the action of a phosphatase in the context of phosphatidic acid?
What is produced by the action of a phosphatase in the context of phosphatidic acid?
Which of the following molecules is a precursor for the synthesis of phosphatidic acid?
Which of the following molecules is a precursor for the synthesis of phosphatidic acid?
How is phosphatidic acid described in terms of its formation from glycerol-3-phosphate?
How is phosphatidic acid described in terms of its formation from glycerol-3-phosphate?
What is the primary function of fat in biological systems?
What is the primary function of fat in biological systems?
In terms of energy expenditure during exercise, which energy source is primarily utilized first?
In terms of energy expenditure during exercise, which energy source is primarily utilized first?
Which characteristic of lipids is essential for biological membranes?
Which characteristic of lipids is essential for biological membranes?
What role do fats play in relation to thermal insulation?
What role do fats play in relation to thermal insulation?
Which of the following processes is linked to the storage of energy in fat cells?
Which of the following processes is linked to the storage of energy in fat cells?
Which statement about the function of lipids is incorrect?
Which statement about the function of lipids is incorrect?
What dual purpose do fats serve in animal cells?
What dual purpose do fats serve in animal cells?
What is a consequence of excessive fat storage in cells?
What is a consequence of excessive fat storage in cells?
What is the primary advantage of storing energy as fatty acids compared to sugars or amino acids?
What is the primary advantage of storing energy as fatty acids compared to sugars or amino acids?
Which of the following statements about fats is incorrect?
Which of the following statements about fats is incorrect?
What role do bile salts play in lipid metabolism?
What role do bile salts play in lipid metabolism?
Why can fatty acids pack more closely in storage tissues compared to monosaccharides?
Why can fatty acids pack more closely in storage tissues compared to monosaccharides?
What ultimately happens to dietary fats after absorption?
What ultimately happens to dietary fats after absorption?
What is the main characteristic that distinguishes fatty acids from sugars in terms of energy storage?
What is the main characteristic that distinguishes fatty acids from sugars in terms of energy storage?
What is the primary source of fats in the human diet?
What is the primary source of fats in the human diet?
How do fatty acids contribute to thermogenesis in brown adipocytes?
How do fatty acids contribute to thermogenesis in brown adipocytes?
What is the primary location where very-long-chain fatty acids begin β-oxidation?
What is the primary location where very-long-chain fatty acids begin β-oxidation?
How does the process of β-oxidation in peroxisomes differ from that in mitochondria?
How does the process of β-oxidation in peroxisomes differ from that in mitochondria?
What is produced during the first step of β-oxidation in peroxisomes?
What is produced during the first step of β-oxidation in peroxisomes?
Which of the following statements about ω-oxidation is true?
Which of the following statements about ω-oxidation is true?
Which biochemical molecule does β-oxidation in mitochondria reduce during its initial step?
Which biochemical molecule does β-oxidation in mitochondria reduce during its initial step?
What is the effect of hydrogen peroxide generated in peroxisomes during β-oxidation?
What is the effect of hydrogen peroxide generated in peroxisomes during β-oxidation?
Why might fatty acid oxidation in peroxisomes be less energy-efficient than in mitochondria?
Why might fatty acid oxidation in peroxisomes be less energy-efficient than in mitochondria?
What unique property distinguishes the β-oxidation occurring in peroxisomes from that in mitochondria?
What unique property distinguishes the β-oxidation occurring in peroxisomes from that in mitochondria?
Which type of fatty acids is activated to form palmitoyl-CoA?
Which type of fatty acids is activated to form palmitoyl-CoA?
How many cycles are needed to convert palmitoyl-CoA into acetyl-CoA?
How many cycles are needed to convert palmitoyl-CoA into acetyl-CoA?
What is the ATP yield from the oxidation of 8 acetyl-CoA in the TCA cycle?
What is the ATP yield from the oxidation of 8 acetyl-CoA in the TCA cycle?
What is produced from the oxidation of 7 FADH2?
What is produced from the oxidation of 7 FADH2?
Which enzyme is associated with carnitine metabolism in fatty acid transport?
Which enzyme is associated with carnitine metabolism in fatty acid transport?
What is the primary product of the fatty acid oxidation step involving palmitoyl-CoA?
What is the primary product of the fatty acid oxidation step involving palmitoyl-CoA?
In the process of fatty acid oxidation, how many equivalents of NADH are generated from 8 acetyl-CoA?
In the process of fatty acid oxidation, how many equivalents of NADH are generated from 8 acetyl-CoA?
Which fatty acid chain length is associated with peroxisomal oxidation?
Which fatty acid chain length is associated with peroxisomal oxidation?
What is the role of CoA-SH in the reaction involving the conversion of palmitoyl-CoA?
What is the role of CoA-SH in the reaction involving the conversion of palmitoyl-CoA?
What molecule is created along with other products when palmitoyl-CoA reacts with 7 NAD+?
What molecule is created along with other products when palmitoyl-CoA reacts with 7 NAD+?
What can acetyl-CoA be readily converted into?
What can acetyl-CoA be readily converted into?
Which transport mechanism is primarily involved in moving acetyl-CoA out of mitochondria?
Which transport mechanism is primarily involved in moving acetyl-CoA out of mitochondria?
What is NOT a product of acetyl-CoA metabolism?
What is NOT a product of acetyl-CoA metabolism?
What molecule serves as an electron donor for fatty acid synthesis?
What molecule serves as an electron donor for fatty acid synthesis?
What process does pyruvate dehydrogenase primarily facilitate?
What process does pyruvate dehydrogenase primarily facilitate?
Which molecule is a key high-energy metabolite generated in glycolysis?
Which molecule is a key high-energy metabolite generated in glycolysis?
How are the reductive equivalents supplied for fatty acid synthesis from acetyl-CoA?
How are the reductive equivalents supplied for fatty acid synthesis from acetyl-CoA?
Which of the following is a necessary component in the transport of acetyl-CoA from mitochondria to cytosol?
Which of the following is a necessary component in the transport of acetyl-CoA from mitochondria to cytosol?
Which molecule is primarily utilized as a carbon source for the synthesis of fatty acids from acetyl-CoA?
Which molecule is primarily utilized as a carbon source for the synthesis of fatty acids from acetyl-CoA?
What is the primary role of cytochrome b5 in the desaturation reaction?
What is the primary role of cytochrome b5 in the desaturation reaction?
Which molecules are involved in the reduction of Fe3+ to Fe2+ during fatty acid desaturation?
Which molecules are involved in the reduction of Fe3+ to Fe2+ during fatty acid desaturation?
What is the overall outcome of the fatty acyl desaturation cycle in terms of electron transfer?
What is the overall outcome of the fatty acyl desaturation cycle in terms of electron transfer?
What is the effect of malonyl CoA on fatty acid transport?
What is the effect of malonyl CoA on fatty acid transport?
Which signal promotes the dephosphorylation and activation of ACC?
Which signal promotes the dephosphorylation and activation of ACC?
Which of the following serves as an allosteric modulator of acetyl-CoA carboxylase?
Which of the following serves as an allosteric modulator of acetyl-CoA carboxylase?
What is produced as a byproduct of the fatty acyl desaturation process?
What is produced as a byproduct of the fatty acyl desaturation process?
What initiates the phosphorylation of ACC leading to its inhibition?
What initiates the phosphorylation of ACC leading to its inhibition?
What role does O2 play in the fatty acyl desaturation cycle?
What role does O2 play in the fatty acyl desaturation cycle?
Which enzyme is activated by the action of insulin related to fatty acid synthesis?
Which enzyme is activated by the action of insulin related to fatty acid synthesis?
What is the purpose of dephosphorylating glucose-6-phosphate in the liver?
What is the purpose of dephosphorylating glucose-6-phosphate in the liver?
What is the catalytic mechanism of glycogen phosphorylase designed to achieve?
What is the catalytic mechanism of glycogen phosphorylase designed to achieve?
What happens to the active site of glycogen phosphorylase during its action?
What happens to the active site of glycogen phosphorylase during its action?
What is the primary product of the reaction catalyzed by glucose-6-phosphate?
What is the primary product of the reaction catalyzed by glucose-6-phosphate?
Which of the following statements is true about the treatment of glucose-6-phosphate?
Which of the following statements is true about the treatment of glucose-6-phosphate?
What is the primary function of glycogen phosphorylase in glycogen metabolism?
What is the primary function of glycogen phosphorylase in glycogen metabolism?
What role does glycogen synthase play in glycogen metabolism?
What role does glycogen synthase play in glycogen metabolism?
What is the function of branching and debranching enzymes in glycogen metabolism?
What is the function of branching and debranching enzymes in glycogen metabolism?
Which type of linkage does glycogen branching enzyme primarily form?
Which type of linkage does glycogen branching enzyme primarily form?
What structural feature distinguishes the nonreducing ends of glycogen chains?
What structural feature distinguishes the nonreducing ends of glycogen chains?
What is the role of pyridoxal phosphate (PLP) in glycogen phosphorylase activity?
What is the role of pyridoxal phosphate (PLP) in glycogen phosphorylase activity?
Which statement best describes the function of the 5'-phosphate group of PLP in relation to glycogen phosphorylase?
Which statement best describes the function of the 5'-phosphate group of PLP in relation to glycogen phosphorylase?
What structural feature does glycogen phosphorylase have that is essential for its function?
What structural feature does glycogen phosphorylase have that is essential for its function?
Which of the following best describes the catalytic function of glycogen phosphorylase?
Which of the following best describes the catalytic function of glycogen phosphorylase?
What is the correct sequence of events that occurs when glycogen phosphorylase is activated?
What is the correct sequence of events that occurs when glycogen phosphorylase is activated?
What happens when blood glucose levels rise significantly?
What happens when blood glucose levels rise significantly?
What is the primary role of glucagon in blood glucose regulation?
What is the primary role of glucagon in blood glucose regulation?
Which condition is associated with hypoglycemia?
Which condition is associated with hypoglycemia?
What triggers the release of epinephrine during stress?
What triggers the release of epinephrine during stress?
What role does the pituitary gland play in hormonal control?
What role does the pituitary gland play in hormonal control?
What is the primary effect of insulin on glucose in the body?
What is the primary effect of insulin on glucose in the body?
Which of the following states is defined by high blood glucose levels?
Which of the following states is defined by high blood glucose levels?
Why is maintaining blood glucose levels critical for brain function?
Why is maintaining blood glucose levels critical for brain function?
What is the primary mechanism through which glycogen degradation occurs?
What is the primary mechanism through which glycogen degradation occurs?
Which enzyme is crucial for the synthesis of glycogen from glucose?
Which enzyme is crucial for the synthesis of glycogen from glucose?
What type of bonds primarily connect glucose units in the synthesis of glycogen?
What type of bonds primarily connect glucose units in the synthesis of glycogen?
What advantage do the numerous branch points in glycogen provide?
What advantage do the numerous branch points in glycogen provide?
What role does the debranching enzyme serve in glycogen metabolism?
What role does the debranching enzyme serve in glycogen metabolism?
Which statement accurately describes the nonreducing ends of glycogen?
Which statement accurately describes the nonreducing ends of glycogen?
What is generated during glycogen degradation at the nonreducing ends?
What is generated during glycogen degradation at the nonreducing ends?
What is the function of glycogen phosphorylase in glycogen metabolism?
What is the function of glycogen phosphorylase in glycogen metabolism?
Which component acts as a substrate for both glycogen degradation and synthesis?
Which component acts as a substrate for both glycogen degradation and synthesis?
What type of reaction generates glucose-6-phosphate from glycogen?
What type of reaction generates glucose-6-phosphate from glycogen?
What is the effect of glucose binding to glycogen phosphorylase a?
What is the effect of glucose binding to glycogen phosphorylase a?
Which of the following correctly represents a step in glycogen degradation?
Which of the following correctly represents a step in glycogen degradation?
What is the primary advantage of phosphorolytic cleavage during glycogenolysis?
What is the primary advantage of phosphorolytic cleavage during glycogenolysis?
What is the purpose of the transferase enzyme in glycogen breakdown?
What is the purpose of the transferase enzyme in glycogen breakdown?
Which statement accurately describes α-1,6-glucosidase activity?
Which statement accurately describes α-1,6-glucosidase activity?
What type of enzyme combines the transferase and α-1,6-glucosidase activities in eukaryotes?
What type of enzyme combines the transferase and α-1,6-glucosidase activities in eukaryotes?
Which compound is released during phosphorolytic cleavage of glycogen?
Which compound is released during phosphorolytic cleavage of glycogen?
Why is the equilibrium in glycogen degradation shifted towards the products?
Why is the equilibrium in glycogen degradation shifted towards the products?
Which molecule ultimately serves as the substrate for the action of glycogen phosphorylase?
Which molecule ultimately serves as the substrate for the action of glycogen phosphorylase?
What process occurs after glucose 1-phosphate is released from glycogen?
What process occurs after glucose 1-phosphate is released from glycogen?
Flashcards
Lipid Classes
Lipid Classes
Lipids are categorized based on their chemical structures.
Energy Storage Lipids
Energy Storage Lipids
Some lipids store and generate energy.
Membrane Lipids
Membrane Lipids
Lipids form biological membranes.
Glycerol Backbone
Glycerol Backbone
Signup and view all the flashcards
Fatty Acids
Fatty Acids
Signup and view all the flashcards
Phospholipids
Phospholipids
Signup and view all the flashcards
Glycerophospholipids
Glycerophospholipids
Signup and view all the flashcards
Sphingomyelins
Sphingomyelins
Signup and view all the flashcards
Dihydroxyacetone phosphate (DHAP)
Dihydroxyacetone phosphate (DHAP)
Signup and view all the flashcards
Glycerol-3-phosphate dehydrogenase
Glycerol-3-phosphate dehydrogenase
Signup and view all the flashcards
Phophatidic acid
Phophatidic acid
Signup and view all the flashcards
Diacylglycerol
Diacylglycerol
Signup and view all the flashcards
Triacylglycerol synthesis in intestines
Triacylglycerol synthesis in intestines
Signup and view all the flashcards
Glycerol-3-phosphate
Glycerol-3-phosphate
Signup and view all the flashcards
Acylation
Acylation
Signup and view all the flashcards
What forms Phosphatidic Acid?
What forms Phosphatidic Acid?
Signup and view all the flashcards
CDP-diacylglycerol
CDP-diacylglycerol
Signup and view all the flashcards
What makes CDP-diacylglycerol reactive?
What makes CDP-diacylglycerol reactive?
Signup and view all the flashcards
Palmitoyl-CoA
Palmitoyl-CoA
Signup and view all the flashcards
β-ketosphinganine Synthase
β-ketosphinganine Synthase
Signup and view all the flashcards
β-ketosphinganine Reductase
β-ketosphinganine Reductase
Signup and view all the flashcards
Sphingolipids
Sphingolipids
Signup and view all the flashcards
Ceramide
Ceramide
Signup and view all the flashcards
Cerebrosides
Cerebrosides
Signup and view all the flashcards
Fatty Acyl Chain Modification
Fatty Acyl Chain Modification
Signup and view all the flashcards
Mixed-function oxidase
Mixed-function oxidase
Signup and view all the flashcards
Fatty Acyl Chain Attachment
Fatty Acyl Chain Attachment
Signup and view all the flashcards
Galactose Activation
Galactose Activation
Signup and view all the flashcards
What is Cholesterol's Role?
What is Cholesterol's Role?
Signup and view all the flashcards
How is Mevalonate Formed?
How is Mevalonate Formed?
Signup and view all the flashcards
What's the Rate-Limiting Step?
What's the Rate-Limiting Step?
Signup and view all the flashcards
What are the Key 5-Carbon Intermediates?
What are the Key 5-Carbon Intermediates?
Signup and view all the flashcards
How is Squalene Formed?
How is Squalene Formed?
Signup and view all the flashcards
Acylation (in lipid biosynthesis)
Acylation (in lipid biosynthesis)
Signup and view all the flashcards
How is phosphatidic acid formed?
How is phosphatidic acid formed?
Signup and view all the flashcards
What is the role of diacylglycerol kinase?
What is the role of diacylglycerol kinase?
Signup and view all the flashcards
Why is phosphatidic acid a key intermediate?
Why is phosphatidic acid a key intermediate?
Signup and view all the flashcards
Why is glycerol-3-phosphate important?
Why is glycerol-3-phosphate important?
Signup and view all the flashcards
Energy sources during exercise
Energy sources during exercise
Signup and view all the flashcards
Fat storage and function
Fat storage and function
Signup and view all the flashcards
What makes fat a good energy store?
What makes fat a good energy store?
Signup and view all the flashcards
Thermal insulator
Thermal insulator
Signup and view all the flashcards
Glycerol and fatty acids
Glycerol and fatty acids
Signup and view all the flashcards
Acyltransferases
Acyltransferases
Signup and view all the flashcards
Energy Storage in Fatty Acids
Energy Storage in Fatty Acids
Signup and view all the flashcards
Packing Efficiency of Fats
Packing Efficiency of Fats
Signup and view all the flashcards
Primary Sources of TAGs
Primary Sources of TAGs
Signup and view all the flashcards
Emulsification of Dietary Fats
Emulsification of Dietary Fats
Signup and view all the flashcards
Adipose Cells: Fat Storage
Adipose Cells: Fat Storage
Signup and view all the flashcards
What makes fatty acids good for energy storage?
What makes fatty acids good for energy storage?
Signup and view all the flashcards
Why are fats good for storage?
Why are fats good for storage?
Signup and view all the flashcards
How do we get TAGs?
How do we get TAGs?
Signup and view all the flashcards
Short-Chain Fatty Acids
Short-Chain Fatty Acids
Signup and view all the flashcards
Medium-Chain Fatty Acids
Medium-Chain Fatty Acids
Signup and view all the flashcards
Fatty Acid Beta-Oxidation
Fatty Acid Beta-Oxidation
Signup and view all the flashcards
Carnitine
Carnitine
Signup and view all the flashcards
Acetyl-CoA
Acetyl-CoA
Signup and view all the flashcards
ATP Yield from Fatty Acid Oxidation
ATP Yield from Fatty Acid Oxidation
Signup and view all the flashcards
Saturated Fatty Acids
Saturated Fatty Acids
Signup and view all the flashcards
Unsaturated Fatty Acids
Unsaturated Fatty Acids
Signup and view all the flashcards
Odd-Numbered Carbon Chains
Odd-Numbered Carbon Chains
Signup and view all the flashcards
Fatty Acid Activation
Fatty Acid Activation
Signup and view all the flashcards
Fatty Acid Desaturation
Fatty Acid Desaturation
Signup and view all the flashcards
Desaturase Enzyme
Desaturase Enzyme
Signup and view all the flashcards
Role of Cytochrome b5
Role of Cytochrome b5
Signup and view all the flashcards
O2 in Desaturation
O2 in Desaturation
Signup and view all the flashcards
Insulin's Impact on Fatty Acid Synthesis
Insulin's Impact on Fatty Acid Synthesis
Signup and view all the flashcards
Role of Acetyl-CoA Carboxylase (ACC)
Role of Acetyl-CoA Carboxylase (ACC)
Signup and view all the flashcards
Malonyl-CoA's Inhibitory Effect
Malonyl-CoA's Inhibitory Effect
Signup and view all the flashcards
Citrate's Role in ACC Regulation
Citrate's Role in ACC Regulation
Signup and view all the flashcards
Long Chain Fatty Acids and ACC
Long Chain Fatty Acids and ACC
Signup and view all the flashcards
AMP-Activated Protein Kinase (AMPK)
AMP-Activated Protein Kinase (AMPK)
Signup and view all the flashcards
Peroxisome β-oxidation
Peroxisome β-oxidation
Signup and view all the flashcards
ω-oxidation
ω-oxidation
Signup and view all the flashcards
Hydrogen peroxide production
Hydrogen peroxide production
Signup and view all the flashcards
How does peroxisome β-oxidation differ from mitochondrial β-oxidation?
How does peroxisome β-oxidation differ from mitochondrial β-oxidation?
Signup and view all the flashcards
Why is ω-oxidation an alternative pathway?
Why is ω-oxidation an alternative pathway?
Signup and view all the flashcards
What is the significance of hydrogen peroxide in peroxisomes?
What is the significance of hydrogen peroxide in peroxisomes?
Signup and view all the flashcards
How does ω-oxidation differ from the standard β-oxidation?
How does ω-oxidation differ from the standard β-oxidation?
Signup and view all the flashcards
What is the main function of ω-oxidation?
What is the main function of ω-oxidation?
Signup and view all the flashcards
Acetyl-CoA to Fatty Acids
Acetyl-CoA to Fatty Acids
Signup and view all the flashcards
Acetyl-CoA to Carbohydrates?
Acetyl-CoA to Carbohydrates?
Signup and view all the flashcards
Citrate Shuttle
Citrate Shuttle
Signup and view all the flashcards
Importance of NADH in Fatty Acid Synthesis
Importance of NADH in Fatty Acid Synthesis
Signup and view all the flashcards
Fatty Acid Catabolism
Fatty Acid Catabolism
Signup and view all the flashcards
Mitochondrial Transport of Acetyl-CoA
Mitochondrial Transport of Acetyl-CoA
Signup and view all the flashcards
Role of Pyruvate Dehydrogenase (PDH)
Role of Pyruvate Dehydrogenase (PDH)
Signup and view all the flashcards
Reductant Equivalents for Fatty Acid Synthesis
Reductant Equivalents for Fatty Acid Synthesis
Signup and view all the flashcards
Cantiporter
Cantiporter
Signup and view all the flashcards
Importance of Fatty Acid Synthesis
Importance of Fatty Acid Synthesis
Signup and view all the flashcards
Insulin's role
Insulin's role
Signup and view all the flashcards
Glucagon's role
Glucagon's role
Signup and view all the flashcards
Hormonal regulation of metabolism
Hormonal regulation of metabolism
Signup and view all the flashcards
Epinephrine's role
Epinephrine's role
Signup and view all the flashcards
Hierarchical control
Hierarchical control
Signup and view all the flashcards
Pituitary gland's role
Pituitary gland's role
Signup and view all the flashcards
Adrenal medulla stimulation
Adrenal medulla stimulation
Signup and view all the flashcards
Fuel metabolism
Fuel metabolism
Signup and view all the flashcards
Glycogen Phosphorylase
Glycogen Phosphorylase
Signup and view all the flashcards
Glycogen Synthase
Glycogen Synthase
Signup and view all the flashcards
Branching Enzymes
Branching Enzymes
Signup and view all the flashcards
Debranching Enzymes
Debranching Enzymes
Signup and view all the flashcards
How do glycogen phosphorylase and glycogen synthase work together?
How do glycogen phosphorylase and glycogen synthase work together?
Signup and view all the flashcards
Glycogen Metabolism
Glycogen Metabolism
Signup and view all the flashcards
Glycogen Degradation
Glycogen Degradation
Signup and view all the flashcards
Non-reducing Ends
Non-reducing Ends
Signup and view all the flashcards
Branch Points
Branch Points
Signup and view all the flashcards
Glucose-1-phosphate
Glucose-1-phosphate
Signup and view all the flashcards
UDP-glucose
UDP-glucose
Signup and view all the flashcards
Glucose-6-Phosphate Dephosphorylation
Glucose-6-Phosphate Dephosphorylation
Signup and view all the flashcards
Glycogen Phosphorylase's Challenge
Glycogen Phosphorylase's Challenge
Signup and view all the flashcards
What does glycogen phosphorylase do?
What does glycogen phosphorylase do?
Signup and view all the flashcards
What does glycogen synthase do?
What does glycogen synthase do?
Signup and view all the flashcards
Why is a phosphorolytic reaction important?
Why is a phosphorolytic reaction important?
Signup and view all the flashcards
Allosteric Regulation
Allosteric Regulation
Signup and view all the flashcards
Phosphorylase a
Phosphorylase a
Signup and view all the flashcards
Phosphorylase b
Phosphorylase b
Signup and view all the flashcards
How does glucose affect glycogen phosphorylase?
How does glucose affect glycogen phosphorylase?
Signup and view all the flashcards
Glycogenolysis
Glycogenolysis
Signup and view all the flashcards
What are the steps of glycogenolysis?
What are the steps of glycogenolysis?
Signup and view all the flashcards
Phosphorolytic Cleavage
Phosphorolytic Cleavage
Signup and view all the flashcards
α-1,6-Glucosidase
α-1,6-Glucosidase
Signup and view all the flashcards
What makes glycogen phosphorylase a 'good' enzyme?
What makes glycogen phosphorylase a 'good' enzyme?
Signup and view all the flashcards
What is the role of pyridoxal phosphate (PLP) in glycogen phosphorylase?
What is the role of pyridoxal phosphate (PLP) in glycogen phosphorylase?
Signup and view all the flashcards
What is the difference between glycogen phosphorylase and glycogen synthase?
What is the difference between glycogen phosphorylase and glycogen synthase?
Signup and view all the flashcards
Study Notes
Metabolism of Glycolipids, Isoprenoids, and Steroids
- Topic: Lipid metabolism, specifically focusing on glycolipids, isoprenoids, and steroids.
- Speaker: Dr. Ardina Grüber, Nanyang Technological University
- Focus: Structures and classifications of various lipid classes.
Structure and Classification of Lipids
- Simple Esters (RCOOR'): Includes substances like waxes.
- Triacylglycerols (Neutral Fats): Triesters of glycerol.
- Glycerophospholipids: Contain charged phosphate groups.
- Sphingolipids: Derivatives of sphingosine (an amino alcohol).
- Sphingomyelins: Contain charged phosphate groups.
- Glycolipids: Contain sugar groups.
- Steroids: Based on a 20-carbon acid.
Structure and Classification of Lipids Details
- Glycerolipids:
- Triacylglycerols: Storage forms of fatty acids. Examples include adipose stores and blood lipoproteins.
- Glycerophospholipids: Crucial components of biological membranes.
- Specific examples like phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine, phosphatidylinositol bisphosphate (PIP2), phosphatidylglycerol, and cardiolipin are detailed.
- Phospholipids: Another crucial class of biological membranes.
- Ether glycerolipids: Have ether linkages
- Plasmalogens: Special subtype of ether glycerolipids.
- Platelet activating factor: Special lipid plays crucial role in blood clotting.
- Sphingolipids:
- Sphingophospholipids: Specific examples including sphingomyelin are discussed.
- Glycolipids:
- Cerebrosides.
- Sulfatides.
- Globosides.
- Gangliosides.
Glycerolipids and Sphingolipids
- Glycerolipids include triacylglycerols and glycerophospholipids.
- Sphingolipids are crucial components of membranes and precursors of hormones.
- Both are essential structural components of cell membranes.
Pathways in Glycerophospholipid Biosynthesis
- The major phospholipids found in membranes are shown.
- Pathways are found in both bacterial and eukaryotic cells.
- Other reactions are confined to eukaryotic cells.
- Key molecules include dihydroxyacetone phosphate (DHAP), diacylglycerol (DAG), and S-adenosylmethionine (AdoMet).
Glycerolipids Synthesis
- Glycerolipids are synthesized by phosphorylation and acylation of glycerol.
- Glycerokinase catalyzes phosphorylation of glycerol to form glycerol-3-phosphate.
- Glycerol-3-phosphate is acylated at positions 1 and 2 to yield phosphatidic acid.
Dihydroxyacetone Phosphate
- Dihydroxyacetone phosphate (DHAP) is a starting point for eukaryotic synthesis of phosphatidic acid.
- It can be reduced to glycerol-3-phosphate by glycerol-3-phosphate dehydrogenase.
Diacylglycerol and CDP-diacylglycerol
- Diacylglycerol and CDP-diacylglycerol are principal precursors of glycolipids in eukaryotes.
- In eukaryotes, phosphatidic acid is converted either to diacylglycerol (DAG) or CDP-diacylglycerol.
Phosphatidic Acid Activated as CDP-diacylglycerol
- The reaction of CTP with phosphatidic acid is catalyzed by CDP-diacylglycerol synthase.
- This reaction is driven by the enzymatic hydrolysis of pyrophosphate, catalyzed by the ubiquitous pyrophosphatase.
Synthesis of Phospholipids via CDP-diacylglycerol
- Eukaryotes use CDP-diacylglycerol as a precursor for several other phospholipids including phosphatidylinositol (PI), phosphatidylglycerol (PG), and cardiolipin.
Ceramide (Precursor of Sphingolipids)
- Ceramide is a key precursor for sphingolipids.
- The synthesis involves condensation of palmitoyl-CoA and serine followed by reduction with NADPH to yield sphinganine.
Formation of Squalene
- The biosynthesis of squalene involves conversion of mevalonate to isopentenyl pyrophosphate(IPP) and dimethylallyl pyrophosphate (DMAPP)
- IPP and DMAPP form geranyl pyrophosphate and then farnesyl pyrophosphate, which joins to yield squalene.
Cholesterol Synthesis from Squalene
- Squalene monooxygenase converts squalene to squalene-2,3-epoxide.
- 2,3-oxidosqualene lanosterol cyclase catalyzes the second reaction, which involves a succession of 1,2 shifts of hydride ions and methyl groups.
- The synthesis leads to the formation of lanosterol, a precursor to cholesterol. Many steps are required to further convert lanosterol to cholesterol. All enzymes responsible for this are associated with the endoplasmic reticulum.
Cholesterol Fates
- A portion of cholesterol produced in the liver is incorporated into hepatocyte membranes.
- The majority of cholesterol is exported in three forms: biliary cholesterol, bile acids, and cholesteryl esters. Cholesterol is used in steroid hormone synthesis and as a precursor for vitamin D.
Bile Salt Synthesis
- The formation of an α-hydroxyl group at position 7 of cholesterol is a rate-limiting step in bile salt synthesis and is inhibited by bile salts.
- The process involves reduction, hydroxylation, and conversion of hydroxyls to α-hydroxyls.
HDL Fate
- Nascent HDL is synthesized in the liver and intestinal cells.
- HDL exchanges proteins with chylomicrons and VLDL.
- HDL picks up cholesterol from cell membranes and converts it to cholesterol ester.
LDL Receptors in Cholesterol Uptake and Metabolism
- LDL receptors recognize and take up LDL particles that have lipoprotein molecules.
- Cholesterol ester droplets are produced.
- Recycled vesicles return to the cell plasma membrane, releasing cholesterol, amino acids, and other materials.
Cholesterol Precursor of Steroid Hormones
- Cholesterol is the precursor of steroid hormones.
- The desmolase reaction converts cholesterol to pregnenolone, a key step in steroid synthesis.
- Pregnenolone is transported to the endoplasmic reticulum where hydroxyl oxidation and migration to another ring position yield progesterone.
Regulation of Cholesterol Synthesis
- Key regulatory steps include HMG-CoA reductaase and other steps.
- Regulatory factors include insulin, glucagon, and intracellular cholesterol concentration.
Eicosanoids
- Eicosanoids are locally acting signaling molecules derived from C20 fatty acids, primarily arachidonic acid.
- They are short-lived hormones involved in various physiological functions.
Prostaglandins, Thromboxanes and Leukotrienes
- Prostaglandins, thromboxanes, and leukotrienes are crucial eicosanoids derived from arachidonic acid. The enzyme that converts arachidonic acid is called prostaglandin H synthase (PGHS)
- Aspirin inhibits an important step in their synthesis, providing anti-inflammatory effects.
Release of Arachidonic Acid by Phospholipid Hydrolysis
- Release of arachidonic acid can result from hydrolysis of phospholipids, which involves activation of PLA2 and PLC.
Cyclooxygenation of Arachidonic Acid
- All prostaglandins are cyclopentanoic acids derived from arachidonic acid.
- Biosynthesis is initiated by the enzyme prostaglandin H synthase (PGHS), which plays dual roles (cyclooxygenase and peroxidase).
Conversion of Prostaglandin H2 by Different Synthases
- Prostaglandin H2 is a precursor to various prostaglandins, thromboxanes, and prostacyclins.Different enzymes convert PGH2 to these molecules.
Inhibition of Prostaglandin Synthesis by Aspirin
- Aspirin inhibits prostaglandin synthesis by acetylating a serine residue in the enzyme cyclooxygenase (COX).
Ring Identification System Used for Steroids
- Steroids have a ring structure, derived from isoprene molecules, used in biological processes.
Cholesterol Biosynthesis
- Cholesterol biosynthesis involves three main processes: conversion of C2 fragments to a C6 precursor, conversion of six C6 precursors to C30 squalene, and cyclization of squalene and transformation to C27 cholesterol. The different steps in the pathway are discussed.
Synthesis of Mevalonate
- The cholesterol biosynthesis pathway begins in the cytosol with the synthesis of mevalonate from acetyl-CoA.
- The rate-limiting step is catalyzed by HMG-CoA reductase.
Formation of Isopentenyl Pyrophosphate
- Mevalonate is converted to isopentenyl pyrophosphate (IPP) and dimethylallyl pyrophosphate (DMAPP) as part of the cholesterol synthesis pathway.
Formation of Squalene
- IPP and DMAPP condense to form geranyl pyrophosphate and then farnesyl pyrophosphate, then squalene, which is involved in cholesterol synthesis.
Cholesterol Synthesis from Squalene
- The enzyme squalene monooxygenase converts squalene to squalene-2,3-epoxide, and then to lanosterol via 2,3-oxidosqualene lanosterol cyclase, and numerous steps following, which ultimately yields cholesterol.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Related Documents
Description
Explore the fascinating world of lipid metabolism, focusing specifically on glycolipids, isoprenoids, and steroids. This quiz covers the structures and classifications of various lipid classes, including glycerophospholipids and triacylglycerols, providing a comprehensive overview for students of biochemistry.
