Biology Chapter on Water and Metabolism

A change that triggers a homeostatic response.

A specialized structure that detects changes in the internal environment.

The control center processes the information from the receptor and sends output along a pathway to the effector.

Any organ or tissue that helps restore the variable back to its normal set point.

A mechanism in which a change triggers a response that reduces the initial change.

Water is a polar molecule due to its uneven distribution of charges. This leads to attractive forces called hydrogen bonds between water molecules.

Water's strong attraction to itself allows it to hold onto other water molecules, forming a cohesive force. This attraction helps plants transport water from their roots to their leaves.

Water's ability to stick to other surfaces, like the walls of blood vessels, is called adhesion. This is essential for the flow of fluids in the body.

Water's high heat of evaporation means that it takes a lot of energy to make it change from liquid to gas. This helps regulate body temperature and keeps us cool when we sweat.

Although it seems counterintuitive, ice is less dense than liquid water. This is why ice floats on water, crucial for aquatic life.

The fluid environment surrounding the body's cells. It's like a lake that all the cells live in.

The maintenance of a stable internal environment, despite changes in the external environment. It's like a thermostat that keeps the temperature just right.

Changes in the external environment that can affect the internal environment (like temperature, food availability, or toxins).

Internal mechanisms that help maintain homeostasis by counteracting changes to the internal environment. They are like the body's 'control panel'.

The difference between an ideal value (set point) and the actual value of a variable in the internal environment. They are like signals that tell the body to adjust.

The process of breaking down complex molecules into simpler ones, often releasing energy.

The process of building complex molecules from simpler ones, often requiring energy.

The crossroads where catabolic and anabolic pathways intersect, allowing for the interconversion of molecules.

The study of the chemical processes occurring within living organisms, including the structure, function, and interactions of biological molecules.

The study of genes at the molecular level, particularly their structure, expression, and regulation.

A process where a change in a variable triggers a response that amplifies the initial change, unlike negative feedback, which reverses the change.

The constant breakdown and rebuilding of molecules within a cell, essential for maintaining cellular function.

A series of chemical reactions that occur within a cell, converting one molecule into another.

Enzymes that control the rate of metabolic reactions, ensuring a balanced supply and demand of molecules.

A specific value for a variable in the internal environment. It's the target or ideal level that the body aims to maintain.

The ability of the body to detect changes in the internal environment. It's our internal sensors.

Mechanisms within the body that respond to changes in the internal environment. They are 'control centers' that restore balance.

Autotrophs use light energy and synthesize organic compounds from CO₂ and H₂O.

Heterotrophs obtain energy by oxidizing organic compounds ingested from other organisms.

Both autotrophs and heterotrophs use catabolic reactions (breakdown) and anabolic reactions (synthesis) to obtain and utilize energy.

Autotrophs release oxygen as a byproduct of photosynthesis, while heterotrophs consume oxygen for respiration.

Autotrophs obtain carbon from CO₂, while heterotrophs obtain it from organic compounds.

Reactions involved in the building of larger molecules from smaller ones, like proteins and carbohydrates, requiring energy.

Reactions involved in the breaking down of large molecules into smaller ones, like digestion, releasing energy.

The relative amount of specific molecules in a cell remains stable even though individual molecules are being constantly broken down and rebuilt. It's like maintaining the same number of cars in a parking lot even though cars are constantly arriving and leaving.

Molecules with a faster turnover are constantly broken down and replaced, while molecules with a slower turnover last longer.

Carbohydrates and amino acids have a rapid turnover, meaning they are broken down and rebuilt quickly.

Lipids and nucleic acids (especially DNA) have a slower turnover, meaning they are broken down and rebuilt more slowly.

The rate of metabolic turnover varies depending on the type of molecule and the organ it's in.