Characteristics of Life
The type of reproduction that bacteria use.
What is Asexual Reproduction?
Unlike hydrophobic substances, which are nonpolar and repel water, these polar or ionic substances readily dissolve in or attract water molecules.
What are hydrophilic substances?
In a uniform mixture or solution, this is the term given to the specific substance—such as salt or sugar—that gets dissolved by the solvent.
What is a solute?
While structural forms like cellulose provide support, these biomolecules serve as the primary source of immediate, short-term energy for cellular activity.
What are carbohydrates?
Unlike carbohydrates or proteins, these macromolecules lack true polymers, but they are built primarily from glycerol and fatty acid monomers.
What are lipids?
Sweating on a hot day or shivering in the cold are ways the body works to maintain this steady internal state.
What is homeostasis?
Because ice floats on top of a frozen lake instead of sinking, it forms an insulating layer that prevents the liquid water below from freezing solid, allowing aquatic life to survive the winter.
What is density?
Strong cohesive forces and hydrogen bonding between water molecules at the surface create an elastic-like "film" that lets light insects walk across water without sinking.
What is surface tension?
Unlike carbohydrates, these nonpolar macromolecules serve as the body's primary long-term energy reserve and provide approximately 9 calories per gram.
What are lipids?
Composing the primary barrier of cell membranes, this amphipathic molecule consists of a hydrophilic glycerol and phosphate head attached to two hydrophobic fatty acid tails.
What is a phospholipid?
To be considered scientifically alive, an organism must possess this many of the 8 characteristics of life.
What is 8?
Both of these phenomena occur because water molecules stick to other polar surfaces, a property that works alongside cohesion.
What is adhesion?
Because they are nonpolar and cannot form hydrogen bonds with water, these "water-fearing" substances repel water and will not dissolve in aqueous solutions.
What are hydrophobic substances?
Unlike carbohydrates or nucleic acids, this class of macromolecules lacks a single "main job" because its 20 amino acid monomers fold into thousands of distinct shapes to drive enzymes, structure, transport, and immunity.
What are proteins?
This dynamic, selectively permeable barrier surrounding all cells is formed by a double layer of phospholipids with embedded proteins.
What is the cell membrane (or plasma membrane)?
This term encompasses all the chemical reactions an organism must carry out to maintain life and process energy.
What is metabolism?
Characterized by an unequal sharing of electrons, this property gives water molecules a partial negative charge on one end and a partial positive charge on the other.
What is polarity?
When salt dissolves in water, the salt is the solute, while water—the substance doing the dissolving—acts as this.
What is the solvent?
This macromolecule's primary job is to store and transfer the genetic code necessary to build proteins and pass traits to offspring.
What is Nucleic Acids?
This chemical bond connects one amino acid to another to build a protein chain.
What is a peptide bond?
A plant bending its stem to grow toward sunlight demonstrates this characteristic of life.
What is responding to stimuli?
These six essential elements—often remembered by the acronym CHNOPS—make up over 97% of the mass of most living organisms.
What are Carbon, Hydrogen, Nitrogen, Oxygen, Phosphorus, and Sulfur?
Derived from Greek roots meaning "water-loving," this term describes polar or ionic molecules that readily interact with and dissolve in water.
What is hydrophilic?
Unlike carbohydrates, fats, and proteins, this is the exact number of usable calories per gram that nucleic acids provide to the body for dietary energy.
What is zero?
These are the three fundamental chemical subunits that bond together to form a single nucleotide monomer.
What are a phosphate group, a 5-carbon sugar, and a nitrogenous base?