Fundamentals of Biology: Cells, Metabolism, and Diet

Posted on Dec 20, 2024 in Biology

What is Biology?

Biology is the study of living organisms, their structure, evolution, functioning, distribution, and interrelationships. The term “Biology” derives from two Greek words: Bios, meaning life, and Logos, meaning study.

What are Biologists?

Biologists are scientists who conduct research related to this natural science. They study the structure, function, growth, origin, evolution, and distribution of living organisms.

Where Do Biologists Work?

Biologists work in a variety of settings, including:

• Laboratories
• Industries
• Fields
• Zoos

What Do Biologists Do?

Biologists carry out a wide range of activities, such as:

• Discovering diseases
• Developing new theories
• Writing articles and books
• Discovering new treatments

Specializations in Biology

Here are some specializations within the field of biology:

• Biochemists: Study the chemical reactions that occur in living organisms.
• Botanists: Study plants.
• Cellular Biologists: Study the basic cellular units of living organisms.
• Ecologists: Study how organisms interact with their environment.
• Evolutionary Biologists: Study the origins and changes in the diversity of life over time.
• Geneticists: Study heredity (how DNA passes from one generation to another, from parents to their offspring).
• Molecular Biologists: Study the biological molecules that make up living organisms.
• Physiologists: Study the function and mechanisms that work within living organisms and their parts.
• Zoologists: Study animals, including animal behavior.

The Scientific Method and Lab Reports

The Scientific Method

The scientific method is a systematic approach to understanding the natural world. It typically involves the following steps:

1. State a problem or ask a question.
2. Formulate a hypothesis.
3. Test the hypothesis through experiments.
4. Draw a conclusion.
5. Develop a new hypothesis (if necessary).

Lab Reports

Lab reports are written documents that describe the process and results of an experiment. They usually include the following sections:

1. Research question
2. Hypothesis
3. Materials and methods
4. Results and data analysis
5. Discussion
6. Conclusion

Scientific vs. Pseudoscientific Statements

Scientific statements are based on empirical evidence and can be tested through observation and experimentation. Examples include:

• The sun warms the Earth unevenly.
• Snow occurs at temperatures of 32°F or below.

Pseudoscientific statements may appear scientific but lack empirical evidence or cannot be tested. Examples include:

• It’s always sunny in Southern California.
• I’m 100% safe from lightning in my house.

Statistical Measures in Biology

Statistical measures are often used in biology to analyze data. Some common measures include:

• Mean: The sum of all values divided by the number of values.
• Median: The middle value when the data is arranged in order.
• Mode: The value(s) that appear most frequently in the data set.

The Pig Digestive System

The pig’s digestive system is vital for the animal’s survival. It ensures that nutrients from food are absorbed, providing energy for growth and cell repair.

Main Organs of the Pig Digestive System

• Mouth: Used for chewing.
• Esophagus: Transports food to the stomach.
• Stomach: Where digestion begins.
• Liver: Plays a role in metabolic processes.
• Pancreas: Aids in digestion.
• Small Intestine: Where nutrients are absorbed.
• Large Intestine: Where fermentation occurs and feces are formed.

Maintaining a Healthy Digestive System in Pigs

To keep a pig’s digestive system healthy, it’s important to provide the right amount of healthy food, ensure adequate water intake, and supply necessary nutrients.

Cells: The Basic Units of Life

A cell is the basic structural, functional, and biological unit of all known organisms. It is the smallest unit of life.

Animal Cells

Animal cells contain various organelles, each with specific functions:

• Centriole: Aids in cell division.
• Ribosomes: Synthesize proteins.
• Cytoplasm: Jelly-like liquid that holds organelles in place.
• Smooth ER: Creates lipids and fats.
• Rough ER: Transports and stores proteins.
• Nucleus: Contains DNA and RNA, responsible for growth and reproduction.
• Lysosome: Contains digestive enzymes.
• Cell Membrane: Controls which substances can enter or leave the cell.
• Mitochondria: The powerhouse of the cell, produces ATP (energy).
• Vacuole: Stores water, food, and waste.
• Golgi Apparatus: Modifies and packages proteins for export.
• Vesicle: Small membrane sacs that move products within, into, or out of the cell.

Plant Cells

Plant cells have most of the same organelles as animal cells, except for lysosomes and centrioles. They also have:

• Cell Wall: Rigid structure surrounding the cell membrane, providing support.
• Chloroplast: Produces food for plants by absorbing sunlight (conducts photosynthesis).

Using a Microscope

Here are the steps for using a microscope:

1. Plug the microscope into a power source.
2. Turn on the light.
3. Place a sample under the stage clips on the stage and center it.
4. Rotate the lens to 4x and listen for the click.
5. Use the coarse adjustment knob to make the image clear.
6. Use the fine adjustment knob to make the image HD.
7. Observe the sample and record results and characteristics.
8. Change the lens to 10x and listen for the click.
9. Repeat steps 6 and 7.
10. Change the lens to 40x and listen for the click.
11. Repeat steps 6 and 7.
12. Remove the sample from the stage clips.
13. Turn off the light and unplug the microscope.

Note: For 10x and 40x lenses, only use the fine adjustment knob.

Metabolism: Chemical Reactions in Living Organisms

Metabolism is the sum of all chemical reactions within the cells of living organisms. It allows organisms to transform chemical energy stored in molecules into energy that can be used for cellular processes. It also provides organisms with energy and helps eliminate waste from chemical reactions.

Macromolecules and Metabolic Reactions

Macromolecules are either built up or broken down through metabolic reactions, such as:

• Food to energy
• Energy to proteins
• Proteins to waste

Enzymes: Catalysts of Metabolism

Enzymes are proteins that speed up chemical reactions. They are crucial in metabolism because they break down large nutrient molecules (proteins, fats, carbohydrates) into smaller molecules.

Anabolic Reactions

Anabolic reactions build up macromolecules and require energy. Examples include:

1. Glycerol reacting with fatty acids to create lipids.
2. Carbon dioxide and water reacting to form glucose and oxygen during photosynthesis.

Catabolic Reactions

Catabolic reactions break down food molecules into smaller units, releasing energy. Examples include:

1. In respiration, glucose is broken down to form carbon dioxide and water.
2. The breakdown of fat in adipose tissue to form fatty acids.

Components of a Well-Balanced Diet

A well-balanced diet should include a variety of foods that provide essential nutrients. These nutrients can be broadly classified into carbohydrates, lipids, and proteins.

Examples of Food Consumed During the Holidays

Here are some examples of food items consumed during the holidays, along with their ingredients classified as carbohydrates, lipids, or proteins: