Chemistry Of Cells Flashcards
What is obesity?
Obesity is called America’s #1 disease, with almost 40% of U.S. adults classified as obese in 2020
Obesity rates have been increasing over the past several decades.
What does Body Mass Index (BMI) estimate?
BMI estimates body fat based on height and weight
Healthy: BMI 19-24, Overweight: BMI 25-29, Obese: BMI 30+.
What is the problem of obesity?
Obesity is a problem of energy imbalance, where energy intake over time exceeds energy expenditure.
What is the definition of calories (lower case c)?
Calories are the amount of energy required to raise the temperature of 1 g of water by 1 °C.
What are calories (capital C)?
Calories (C) equal to 1000 calories, or 1 kilocalorie (kcal).
What role does food play in energy?
Food is a source of energy and contains macromolecules that are broken down into building blocks or subunits.
What is NEAT?
NEAT stands for nonexercise activity thermogenesis, which includes daily activities like yard work, shopping, and walking the dog.
How does sitting affect caloric burn?
Obese individuals sat 2.25 hours longer than lean individuals, who burned +350 Calories per day by sitting less.
What is cellular respiration?
Cellular respiration is a series of reactions that converts stored food energy into ATP.
What are the three major stages of cellular respiration?
The three major stages are:
* Glycolysis
* Kreb’s / Citric acid cycle
* Electron transport chain.
Where does glycolysis occur?
Glycolysis occurs in the cytoplasm and does not require oxygen.
What does glycolysis produce?
Glycolysis breaks down glucose into two pyruvate molecules and produces a little bit of ATP.
What happens in the Kreb’s cycle?
The Kreb’s cycle, which occurs in the mitochondria, extracts high-energy electrons and releases CO2.
What is the function of the electron transport chain?
Electrons are passed down a chain of molecules to oxygen, producing most of the ATP.
What occurs when oxygen consumption exceeds oxygen intake?
Aerobic respiration stops and an anaerobic process called fermentation comes into play.
What are the products of fermentation?
Fermentation produces lactic acid (in bacteria and humans) or alcohol (in yeast).
What is the purpose of fermentation?
The purpose of fermentation is to regenerate NAD+ when oxygen is scarce.
What are the possible pathways of glucose breakdown?
Glucose can be broken down into:
* 2 pyruvate (2 ATP produced)
* Aerobic respiration (about 34 ATP produced)
* Fermentation (producing alcohol + CO2 or lactic acid).
How is excess energy stored in animals?
Animals store extra energy as:
* Glycogen in muscle and liver cells (short-term)
* Triglycerides in fat cells (long-term).
What happens to energy according to the law of conservation?
Energy is never destroyed, only converted from one form to another.
What results from excess energy?
Excess energy results in obesity.
