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1. Introduction to Anatomy & Physiology5h 43m
2. Cell Chemistry & Cell Components12h 36m
3. Energy & Cell Processes10h 6m
4. Tissues & Histology10h 3m
5. Integumentary System2h 20m
6. Bones & Skeletal Tissue2h 16m
7. The Skeletal System2h 35m
8. Joints2h 17m
9. Muscle Tissue2h 33m
10. Muscles1h 11m
11. Nervous Tissue and Nervous System1h 35m
12. The Central Nervous System1h 6m
- Introduction to the Central Nervous System
  18m
- The Cerebrum
  48m
13. The Peripheral Nervous System1h 26m
14. The Autonomic Nervous System1h 38m
15. The Special Senses2h 41m
16. The Endocrine System2h 48m
17. The Blood3h 22m
18. The Heart2h 42m
19. The Blood Vessels3h 35m
20. The Lymphatic System3h 16m
21. The Immune System14h 37m
22. The Respiratory System3h 20m
23. The Digestive System2h 5m
24. Metabolism and Nutrition4h 0m
25. The Urinary System2h 39m
26. Fluid and Electrolyte Balance, Acid Base Balance37m
27. The Reproductive System2h 5m
28. Human Development1h 21m
29. Heredity3h 32m

3. Energy & Cell Processes

Introduction to Energy

3. Energy & Cell Processes

Introduction to Energy: Videos & Practice Problems

Video Lessons Practice Worksheet

Topic summary

Energy is the ability to perform work, with two main types: potential energy, which is stored energy available to cause change, and kinetic energy, the energy of motion. Examples include gravitational potential energy, as seen in a biker at the top of a hill, and chemical potential energy found in glucose. Thermodynamics studies energy transfers between systems and surroundings, where the system is the focus of study, and surroundings encompass everything else. Biological systems, like plants, can exchange energy and mass, exemplified by photosynthesis, where solar energy and carbon dioxide enter, and glucose and oxygen exit.

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Introduction to Energy

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Introduction to Energy Video Summary

Energy is fundamentally defined as the ability to perform work, which in biological contexts refers to the transfer of energy that results in an overall change within a living system. In this exploration of energy, two primary types are essential: potential energy and kinetic energy.

Potential energy is the stored energy that has the capacity to do work or induce change. This form of energy can manifest in various ways, with gravitational potential energy being a prominent example. Gravitational potential energy is present when an object is elevated in a gravitational field, such as a biker positioned at the top of a hill. Although the biker is stationary, they possess significant gravitational potential energy due to their height.

Another form of potential energy is chemical potential energy, which is stored in the bonds of molecules. A classic example is glucose, a common sugar that serves as a vital energy source in biological systems.

Kinetic energy, on the other hand, is the energy of motion. Any object in motion, including a biker descending a hill or the muscle contractions involved in physical activities, possesses kinetic energy. For instance, when the biker begins to coast down the hill, the gravitational potential energy they held at the top is converted into kinetic energy, allowing them to accelerate as gravity acts upon them. Once the biker reaches the bottom of the hill, their gravitational potential energy decreases, reflecting their new position.

In summary, understanding the distinction between potential energy, which is stored and ready to be converted into work, and kinetic energy, which is actively in motion, is crucial for grasping the dynamics of energy in biological systems. This foundational knowledge will be built upon in subsequent discussions and applications.

Problem

Which of the following is an example of potential energy?
a) Water rushing over a water fall.
b) A glucose molecule.
c) A spring being released and expanding rapidly.
d) An ant foraging (moving around) for food.

Water rushing over a water fall.

A glucose molecule.

A spring being released and expanding rapidly.

An ant foraging (moving around) for food.

Problem

Which of the following is NOT a form of kinetic energy?
a) When the temperature of a substance rises causing the molecules of that substance to move faster.
b) When a hockey puck slides across the ice after being hit by a player.
c) When glucose molecules are broken down to create energy for cellular work.
d) When the molecules of the air vibrate transmitting soundwaves.

When the temperature of a substance rises causing the molecules of that substance to move faster.

When a hockey puck slides across the ice after being hit by a player.

When glucose molecules are broken down to create energy for cellular work.

When the molecules of the air vibrate transmitting soundwaves.

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Thermodynamics: System vs. Surroundings

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Thermodynamics: System vs. Surroundings Video Summary

Thermodynamics is a crucial field that focuses on the study of energy transfers between different bodies of matter. In this context, it is essential to differentiate between the system and the surroundings. The system refers to the specific portion of matter being studied, which can vary significantly depending on the scenario. For instance, the system might be an entire living organism in one case or a single chemical reaction in another. Conversely, the surroundings encompass everything outside the system, essentially forming the environment in which the system exists.

Biological systems present a fascinating aspect of thermodynamics as they can transfer both energy and mass with their surroundings. For example, consider a plant as a biological system. It can absorb solar energy and essential components like carbon dioxide and water from its surroundings. This energy and mass can enter the plant, facilitating processes such as photosynthesis. During this process, the plant converts solar energy and raw materials into glucose, a form of chemical potential energy, and releases oxygen gas as a byproduct. This illustrates that not only can energy and mass enter a biological system, but they can also exit in different forms.

In summary, understanding the dynamics of systems and surroundings is fundamental in thermodynamics, especially in biological contexts where energy and mass exchanges are vital for processes like photosynthesis. As we progress in our studies, we will delve deeper into these concepts and their applications.

Problem

Why are the principles of thermodynamics important for the study of biology?
a) The principles of thermodynamics govern the chemical processes in all biological organisms.
b) The principles of thermodynamics govern how an organism exchanges energy with their environment.
c) The principles of thermodynamics govern how all life on Earth exchanges energy.
d) All of the above.

The principles of thermodynamics govern the chemical processes in all biological organisms.

The principles of thermodynamics govern how an organism exchanges energy with their environment.

The principles of thermodynamics govern how all life on Earth exchanges energy.

All of the above.

Problem

Which of the following is NOT an example of a biological system?
a) A human eating a cheeseburger.
b) A coral reef where energy and mass both enter and exit.
c) The digestive system of an organism absorbing food energy and discarding food waste.
d) The universe where the amount of energy and mass is constant.

A human eating a cheeseburger.

A coral reef where energy and mass both enter and exit.

The digestive system of an organism absorbing food energy and discarding food waste.

The universe where the amount of energy and mass is constant.

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Here’s what students ask on this topic:

What is the difference between potential energy and kinetic energy in biological systems?

Potential energy is stored energy that has the capacity to cause change, while kinetic energy is the energy of motion. In biological systems, potential energy can be found in chemical bonds, such as those in glucose molecules, which store energy for later use. Gravitational potential energy is another example, like a biker at the top of a hill. Kinetic energy, on the other hand, is observed in moving objects or processes, such as muscle contractions when you flex your arm or walk. Importantly, potential energy can be converted into kinetic energy, as seen when the biker starts moving downhill, transforming stored gravitational energy into motion energy.

How do biological systems transfer energy and mass with their surroundings?

Biological systems, such as plants, can exchange both energy and mass with their surroundings. For example, during photosynthesis, plants absorb solar energy (energy input) and mass in the form of carbon dioxide (CO₂) and water (H₂O). These inputs are converted into glucose, which stores chemical potential energy, and oxygen (O₂), which are released back into the surroundings. This process demonstrates how energy and mass can enter and exit a biological system, emphasizing the dynamic interaction between the system and its environment.

What is the role of glucose in storing chemical potential energy?

Glucose plays a crucial role in storing chemical potential energy in biological systems. The energy is stored in the chemical bonds of the glucose molecule, which can be broken down during cellular respiration to release energy for cellular processes. This stored energy is essential for activities such as muscle contractions, cell division, and maintaining homeostasis. Glucose is a primary energy source because it is abundant and efficiently converted into usable energy forms like ATP (adenosine triphosphate).

What is thermodynamics, and how does it apply to biological systems?

Thermodynamics is the study of energy transfers between different bodies of matter. In biological systems, it focuses on how energy and mass are exchanged between the system (e.g., a plant or a cell) and its surroundings. For instance, during photosynthesis, a plant absorbs solar energy and mass (CO₂ and H₂O) to produce glucose and oxygen. This demonstrates the principles of thermodynamics, where energy and mass flow into and out of the system, enabling life-sustaining processes.

How does gravitational potential energy convert into kinetic energy?

Gravitational potential energy is the energy stored in an object due to its position relative to a gravitational field, such as a biker at the top of a hill. When the biker starts moving downhill, the stored gravitational potential energy is converted into kinetic energy, the energy of motion. This conversion occurs because gravity accelerates the biker downward, transforming the stored energy into movement. This process illustrates the principle of energy conservation, where energy changes form but is not lost.

What is the system and surroundings in thermodynamics?

In thermodynamics, the system refers to the specific portion of matter being studied, such as a living organism, a cell, or a chemical reaction. The surroundings include everything outside the system that interacts with it. For example, in photosynthesis, the plant is the system, while the sunlight, air, and soil are the surroundings. Energy and mass can flow between the system and surroundings, enabling processes like energy absorption and the release of byproducts.