Nutrition and Energy Concepts

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Questions and Answers

What is the primary role of adenosine triphosphate (ATP) in living cells?

To facilitate cellular respiration

To synthesize proteins

To act as a store of energy rich phosphate bonds (correct)

To store genetic information

Which form of energy can living cells utilize?

Chemical energy from carbohydrates

Energy rich phosphate bonds (correct)

Thermal energy

Mechanical energy

Why can living cells not use energy directly from glucose?

Energy from glucose is too unstable

Glucose cannot be transported into cells

They lack enzymes to break down glucose

They can only use energy in the form of energy rich phosphate bonds (correct)

What type of biochemical bond is primarily involved in ATP’s storage of energy?

Energy rich phosphate bonds Signup and view all the answers

In which cellular process is ATP primarily utilized?

Cellular respiration Signup and view all the answers

Which of the following activities are primarily involuntary and essential for survival?

Respiration Signup and view all the answers

What role do involuntary activities play in the human body?

They regulate vital functions without conscious control. Signup and view all the answers

Which of the following is least likely to be classified as an involuntary activity?

Walking Signup and view all the answers

Involuntary activities are crucial for what aspect of human biology?

Homeostasis Signup and view all the answers

Which of the following statements about involuntary activities is true?

They are vital for essential bodily functions. Signup and view all the answers

Which factor does physical activity primarily increase?

Basal metabolic rate (BMR) Signup and view all the answers

Which of the following activities would be considered part of physical activity?

Walking during a park visit Signup and view all the answers

What types of energy expenditures are included in the definition of physical activity?

Energy needed for work, recreation, and mental activity Signup and view all the answers

Which of the following is NOT a component of physical activity?

Involuntary muscle contractions Signup and view all the answers

What is a consequence of increased physical activity on the body?

Increased energy requirement for mental tasks Signup and view all the answers

What does specific dynamic action (SDA) primarily increase?

The energy expenditure related to food processing Signup and view all the answers

Which of the following statements accurately reflects the nature of SDA?

SDA represents the energy cost of processing food. Signup and view all the answers

How is the effect of SDA best characterized in relation to metabolic processes?

It increases metabolic activity beyond fasting levels. Signup and view all the answers

Which factor is NOT a contributor to the effect of SDA?

The body's resting metabolic rate Signup and view all the answers

In what context does SDA typically manifest?

After food consumption and digestion Signup and view all the answers

Which of the following is NOT one of the three forms of physical activities?

High intensity work Signup and view all the answers

What is the primary location where glycogen is stored in the body?

Liver and muscles Signup and view all the answers

Which of the following accurately reflects the amount of glycogen stored in the body?

300 g Signup and view all the answers

What type of physical activity would most likely be considered moderate work?

Cycling at a comfortable pace Signup and view all the answers

Which of the following pairs correctly links a type of physical activity with its corresponding energy store?

Moderate work - Glycogen stores Signup and view all the answers

What is the primary factor that indicates energy balance in the body?

The total energy expended Signup and view all the answers

Which equation correctly represents the concept of energy balance?

Energy output = energy input Signup and view all the answers

If an individual is in a state of energy balance, what is the likely outcome regarding their body weight?

Body weight remains steady Signup and view all the answers

Which of the following best describes the role of food energy in achieving energy balance?

Food energy must equal energy expenditure for weight maintenance Signup and view all the answers

What does a consistent deviation from energy balance suggest about an individual's lifestyle?

A possible reduction in physical activity Signup and view all the answers

Study Notes

Energy

Energy is defined as the ability to do work.
Energy exists in various forms, crucial in nutrition:
- Chemical energy in food
- Light/solar energy for vitamin D synthesis (skin) and photosynthesis (plants)
- Mechanical energy for muscle movement
- Electrical energy for brain and nerve cell function
- Heat energy generated during energy conversion.

Forms of Energy

Energy is stored in the body as high-energy compounds, notably adenosine triphosphate (ATP).
ATP acts as a store of energy-rich phosphate bonds.
Living cells utilize energy in the form of energy-rich phosphate bonds.
When energy is needed for cellular activity, ATP is converted to adenosine diphosphate (ADP).
One mole of ATP yields 8 kcal/33 kJ of energy.
ADP is converted back to ATP by adding phosphate ions, facilitating energy release and transfer.

Energy Value of Food

Physiological fuel value (kcal/g):
- Carbohydrates: 4.0
- Proteins: 4.0
- Fats: 9.0
Potential energy in food (kcal/g):
- Carbohydrates: 4.15
- Proteins: 5.65
- Fats: 9.4

Total Energy Requirement

Total energy needed by a person is the sum of:
- Basal energy needs (BMR)
- Energy effect of food intake (specific dynamic action)
- Energy cost of physical activity.
Energy is required for growth, maintenance, regulating body temperature, and physical/mental activities.

Activities that Need Energy

Activities are classified into:
- Voluntary activities: under individual control (walking, sitting, cycling, dishwashing)
- Involuntary activities: not under individual control (heart beating, respiration, maintaining body temperature)
Total Energy = Basal Metabolic Rate + Specific Dynamic Action + Activity Rate

Basal Metabolic Rate (BMR)

The energy required by the body to carry out involuntary work and maintain body temperature.
Factors affecting BMR:
- Body size
- Body composition
- Age
- Sex
- State of health
- Fever
- Hormones
- Climate

Specific Dynamic Action (SDA)

The effect of food on increasing metabolic rate beyond fasting levels.
Energy is needed for digesting, absorbing, and metabolizing food.

Physical Activity

Physical activity increases BMR.
It includes energy needs for work, recreation, and mental activities.
- Sedentary/light work
- Moderate work
- Heavy work

Energy Stores in the Body

The body stores energy in three forms:
- Glycogen: 300g in muscles, 100g in liver (carbohydrate form)
- Muscles: protein stored in limited amounts
- Adipose tissue: fat stored, amount varies significantly between individuals

Energy Balance

Energy balance is when energy intake approximately equals energy expenditure, maintaining stable body weight
Energy balance: energy output = energy input
Excessive calorie intake relative to output leads to overweight (obesity).
Deficient intake of carbohydrates & fats leads to underweight (under-nutrition).

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Description

This quiz covers the fundamental concepts of energy in nutrition, including its various forms and the role of ATP in energy storage and transfer within cells. Understand how energy values in food influence our physiological processes. Test your knowledge on how energy is utilized in our bodies!