Chapter 6: Dietary Energy and Cellular Respiration

Flashcards about dietary energy and cellular respiration.

What is obesity?

Having more body fat than is considered healthy.

What are some health risks associated with obesity?

Heart disease, diabetes, stroke, high blood pressure (hypertension), and cancer.

What factors can contribute to obesity?

Biology, genetics, medications, chemicals in food, lack of sleep, culture, larger portion sizes, sedentary lifestyle, and social enjoyment.

What is BMI (Body Mass Index)?

An estimate of body fat based on height and weight.

What BMI is considered obese?

BMI ≥ 30.

What BMI is considered overweight?

BMI 25 - 29.9.

Why do we need nutrients from food?

Provide chemical building blocks and energy needed for essential life activities.

What are the main sources of chemical energy in food?

Carbohydrates, proteins, and fats.

What is a calorie (lowercase)?

The amount of energy required to raise the temperature of 1 gram of water by 1°C.

What is a Calorie (capitalized)?

1,000 calories or 1 kilocalorie; common unit of energy used in food nutrition labels.

How many Calories are in a gram of triglycerides (fat)?

9 Calories.

How many Calories are in a gram of protein or carbohydrate?

4 Calories.

What factors influence daily energy needs?

Weight, gender, age, body type, activity levels, and genetics.

According to the principle of conservation of energy, what has to happen to maintain weight?

Calories In = Calories Burned.

According to the principle of conservation of energy, what has to happen to lose weight?

Calories In < Calories Burned.

According to the principle of conservation of energy, what has to happen to gain weight?

Calories In > Calories Burned.

What does NEAT stand for?

Non-exercise activity thermogenesis (NEAT) – the amount of energy expended in everyday activities.

What is ATP?

Adenosine triphosphate; a nucleotide that stores chemical energy in the bonds between its phosphate groups.

What are the two types of cellular respiration?

Aerobic respiration (with oxygen) and anaerobic respiration (without oxygen).

What are the reactants in aerobic respiration?

Glucose (C6H12O6) and oxygen (O2).

What are the products of aerobic respiration?

Carbon dioxide (CO2), water (H2O), and ATP (cellular energy).

What is the role of mitochondria?

Cell’s power plants – required for aerobic respiration.

What are the 3 steps of aerobic respiration?

Glycolysis, citric acid cycle (Krebs cycle), and electron transport chain.

What occurs during glycolysis?

Occurs in the cytoplasm, breaks down glucose into pyruvate, releases a small amount of energy (2 ATP + some NADH).

What occurs during the citric acid cycle (Krebs cycle)?

Occurs in the matrix of mitochondria, breaks down pyruvate, produces carbon dioxide, releases a small amount of energy (2 ATP + some NADH).

Where and how is the electron transport chain used?

Inner membranes of mitochondria; oxygen accepts electrons and combines with H+ to produce water; energy released is used to create many (26-28) ATP.

What happens to carbon dioxide after being produced by cellular respiration?

Travels to the lungs and is exhaled.

What can cells use to fuel aerobic respiration if they don’t have enough glucose?

Fats (fatty acids and glycerol) and amino acids.

What happens if there isn’t enough oxygen?

No O2 → no electron transport chain; pyruvate goes to fermentation (anaerobic respiration).

What happens during fermentation?

Glycolysis converts glucose to pyruvate. Only a small amount of energy is produced (2 ATP).

Why is fermentation still needed if it does not produce much ATP?

Supplies NAD+ for glycolysis.

What is glycogen?

Complex animal carbohydrate - linked chains of glucose; short-term energy storage; stored in muscle and liver cells.

What are triglycerides?

Lipid found in fat cells; stores excess energy for long-term use.

What is the correct order of the stages of aerobic respiration?

Glycolysis → citric acid cycle → electron-transport chain.

Which process does fermentation share with aerobic respiration?

Glycolysis.