Biology Chapter on Feedback Mechanisms

The smallest unit of an element that can exist independently. It's the basic building block of matter.

A pure substance composed of only one type of atom. Examples include iron, gold, and oxygen.

A substance formed when two or more different elements chemically combine in a fixed ratio. Examples include water (H2O) and carbon dioxide (CO2).

The central core of an atom, containing protons and neutrons.

Positively charged particles found in the nucleus of an atom.

Neutral particles found in the nucleus of an atom.

Negatively charged particles orbiting the nucleus of an atom.

Atoms of the same element that have the same number of protons but different numbers of neutrons. For example, Carbon-12 and Carbon-14.

The most important compound in living organisms, making up about two-thirds of an adult's body weight. It facilitates metabolic reactions, transports chemicals, and regulates temperature.

A waste product created during energy production in cells. It is primarily transported in the blood and exhaled by the lungs.

Important inorganic compounds found in body fluids. Examples include sodium, chloride, potassium, calcium, and magnesium. They play crucial roles in regulating metabolism, maintaining fluid balance, and supporting various cellular functions.

A condition where the body's pH becomes too acidic. This can be caused by factors like inefficient carbon dioxide excretion by the lungs.

A condition where the body's pH becomes too alkaline (basic). This can happen due to loss of acidic substances through vomiting, diarrhea, or certain medical treatments.

The ability of one substance to dissolve in another. For example, sugar dissolving in water.

A substance that releases hydrogen ions (H+) when dissolved in water. Examples include lemon juice and vinegar.

A substance that accepts hydrogen ions (H+) when dissolved in water, often releasing hydroxide ions (OH-). Examples include baking soda and soap.

A compound that releases other anions and cations when dissolved in water. For example, sodium chloride (table salt) releases sodium (Na+) and chloride (Cl-) ions.

A reaction between an acid and a base, where the hydrogen ions (H+) from the acid react with the hydroxide ions (OH-) from the base to form water.

A scale that measures the hydrogen ion concentration in a solution. The scale ranges from 0 to 14, with 7 being neutral. Lower pH values indicate a higher concentration of hydrogen ions (more acidic), while higher pH values indicate a lower concentration of hydrogen ions (more alkaline).

Weak acids and bases that help to maintain a stable pH within body fluids by resisting changes in acidity or alkalinity. They act like buffers, absorbing excess hydrogen ions or hydroxide ions.

Ionic compounds that conduct electricity when dissolved in water because they dissociate into charged ions. Examples include sodium chloride and potassium chloride.

A chemical reaction is the process where atoms or molecules rearrange to form new chemical combinations. It involves reactants (starting materials) and products (newly formed substances).

The sum of all chemical reactions occurring within a living organism. It involves breaking down complex molecules (catabolism) to release energy and building new molecules (anabolism) using that energy.

The energy needed to start a chemical reaction. It's like the push you need to get a ball rolling.

A substance that speeds up a chemical reaction without being permanently changed itself. It's like a helper that makes the reaction go faster.

Protein molecules that act as catalysts in biological reactions. They are highly specific for the reactions they control.

The molecule that interacts with an enzyme in a chemical reaction. It's like the target the enzyme works on.

The site on an enzyme where the substrate binds. It's like the lock where the key fits.

A chemical reaction where a complex molecule is broken down into simpler products. It often involves the addition of water (hydrolysis).

A control system that uses the output of a process to regulate its input. This helps maintain a steady state, like regulating body temperature.

A component of the feedback control loop that detects changes in the controlled variable.

A component of the feedback control loop that amplifies and transmits the sensor's signal to the effector.

A component of the feedback control loop that carries out the response to maintain the controlled variable within a set range.

A type of feedback loop where the output of the system amplifies the input, leading to a self-reinforcing cycle.

Proteins are long chains of amino acids folded into complex 3D shapes, crucial for functions like carrying molecules (hemoglobin), acting as enzymes, and forming hormones (insulin).

Proteins are sensitive to changes in pH because hydrogen ions can disrupt their delicate 3D structure, altering their function and potentially damaging living tissues.

Fats (triglycerides), primarily composed of carbon, hydrogen, and oxygen, are stored in adipose tissue and serve as energy sources. They also insulate the body and protect internal organs.

Saturated fats usually remain solid at room temperature while unsaturated fats are liquid, also known as oils.

Phospholipids are crucial components of cell membranes, forming a double layer that creates a water-repellent barrier for the cell.

Steroids, including vital hormones like those produced by gonads, are a group of lipids. Cholesterol, a steroid, helps stabilize cell membranes and is essential for producing other hormones and bile salts for digestion.

Nucleotides are created from a sugar, a base, and a phosphate group. Nucleic acids (DNA and RNA) are the largest molecules in the body and use nucleotides as their building blocks.

Adenosine triphosphate (ATP) is an energy-carrying nucleotide composed of ribose, adenine, and three phosphate groups, often called the "energy currency of the body."