Metabolism Overview Flashcards
What is metabolism?
a) The process of cellular respiration
b) The linked series of biochemical reactions
c) The synthesis of cellular components
d) The generation of ATP within mitochondria
b) linked series of biochem reactions
What is metabolism?
Metabolism is the linked series of biochemical reactions, whose pathways are interdependent and highly regulated.
What are the two broad classes of metabolic reactions, and what do they do?
catabolic reactions and anabolic reactions. Catabolic reactions convert fuels into cellular energy, while anabolic reactions are energy-requiring reactions used to synthesize cellular components or used for movement.
What roles do the central metabolic pathways play?
The central metabolic pathways have both catabolic and anabolic roles. They not only generate ATP through catabolic pathways but also provide building blocks for the synthesis of more complex molecules.
How do cardiac myocytes demonstrate the importance of catabolic metabolism?
The constantly beating heart of cardiac myocytes requires a large, continuous supply of ATP to provide the energy for muscle contraction, highlighting the importance of catabolic metabolism.
Where does the majority of ATP generation occur within our hearts, and what is it linked to?
The majority of ATP generation occurs within mitochondria in our hearts. It is directly linked to O2 utilization and CO2 generation.
Approximately how much ATP do the mitochondria within our hearts generate each day?
~1 kg ATP each day
What happens during a myocardial infarction (MI or heart attack) related to ATP generation?
During a myocardial infarction, if the supply of O2 and nutrients is compromised, not enough ATP will be generated, and the affected tissue will die.
Question: What is metabolism?
a) The process of cellular respiration
b) The linked series of biochemical reactions
c) The synthesis of cellular components
d) The generation of ATP within mitochondria
b
Which of the following best describes catabolic reactions in metabolism?
a) They synthesize cellular components.
b) They require energy for movement.
c) They convert fuels into cellular energy.
d) They occur within the mitochondria.
c
What are the roles of central metabolic pathways?
a) They generate ATP and CO2.
b) They provide building blocks for complex molecules.
c) They regulate cellular respiration.
d) They create anabolic reactions.
b
Where does the majority of ATP generation occur in the heart?
a) In the Z lines of cardiac myocytes
b) Within the sarcomeres of the heart
c) Within the nucleus of cardiac cells
d) Within mitochondria
d
What is the significance of ATP generation in cardiac myocytes?
a) It provides energy for muscle contraction.
b) It directly links to O2 utilization and CO2 generation.
c) It demonstrates the importance of anabolic metabolism.
d) It requires a large supply of nutrients.
a
How much ATP does the mitochondria within our hearts generate approximately each day?
a) 100 grams
b) 500 grams
c) 1 kilogram
d) 10 kilograms
c
What happens during a myocardial infarction (MI or heart attack)?
a) The heart muscle contracts more forcefully.
b) The supply of O2 and nutrients to the heart is compromised.
c) The heart rate decreases significantly.
d) The cardiac myocytes stop beating.
b
What are the three main macronutrients involved in catabolic metabolism?
The three main macronutrients are proteins, carbohydrates, and fats (lipids).
What are the building blocks of proteins, and where are they absorbed?
Proteins are broken down into single amino acids, and they are absorbed in the small intestine.
What is the general chemical formula of carbohydrates, and what are their building blocks?
The general chemical formula of carbohydrates is (CH2O)n, and their building blocks are monosaccharides, such as glucose, fructose, and galactose.
What is starch, and what is the primary carbohydrate stored in plants?
Starch is a polysaccharide made of many glucose monomers, and it is the primary carbohydrate stored in plants.
How is high fructose corn syrup (HFCS) created, and how does its composition compare to sucrose?
HFCS is created by hydrolyzing starch into glucose monosaccharides and converting approximately 50% of the glucose into fructose. Like sucrose, HFCS is chemically similar, as both are composed of half glucose and half fructose.
What happens to digestible disaccharides and polysaccharides once they are consumed?
All digestible disaccharides and polysaccharides are broken down to monosaccharides before being absorbed in the small intestine.
What defines lipids, and what is the most abundant lipid form in our diets?
Lipids are defined by their insolubility in water. The most abundant lipid in our diets is triacylglycerols, commonly known as fat.
What is the major lipid form of energy storage in both plants and animals, and where are large droplets of these lipids found in our bodies?
The major lipid form of energy storage is triacylglycerols. Large droplets of triacylglycerols are found in our adipocytes, which are the most common cell type within adipose or fat tissue.
Why does lipid digestion involve hydrolyzing fatty acids from the glycerol scaffold?
Triacylglycerols cannot cross cell membranes, so they must be broken down into fatty acids and glycerol to be absorbed into cells.
