IndietroFundamentals of Life and Cells- Exam 1
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Termini in questo insieme (20)
Life is a self-sustained chemical system capable of undergoing Darwinian evolution.
Life is membrane delimited, made of cells, stores and follows instructions, stores and uses energy, is self-replicating, controls functions and responds to the environment, and evolves.
Lipids provide membranes that are selectively permeable, enabling compartmentation, energy storage, and insulation.
Nucleic acids store and transmit genetic information essential for life processes.
Proteins control cellular functions and enable responses to the environment.
Energy from sunlight or organic compounds is converted into ATP, which cells use to perform work.
The cell is the smallest unit that meets all properties of life.
Prokaryotes lack a nucleus and membrane-bound organelles, have circular DNA, and are smaller. Eukaryotes have a nucleus, membrane-bound organelles, linear DNA, and are larger.
Viruses store and follow instructions, use energy, replicate, respond, and evolve but are not membrane delimited and do not store energy, so their status as alive is debated.
Monosaccharides like glucose, fructose, and galactose are monomers that form polysaccharides such as glycogen.
Amino acids have an amino group, carboxyl group, hydrogen, and variable side chain (R group) attached to a central carbon.
A peptide bond forms between amino acids by a dehydration reaction linking the carboxyl group of one to the amino group of another.
Proteins fold into structures like alpha helices and beta sheets, which can be parallel or antiparallel.
Cell membranes are composed mainly of a phospholipid bilayer with hydrophilic heads and hydrophobic tails, creating a selective barrier.
Energy from the sun is captured by plants to convert carbon dioxide and water into glucose and oxygen, which animals use for energy.
ATP consists of adenine, ribose sugar, and three phosphate groups; it stores and transfers energy in cells.
Evolution is the change in heritable characteristics of biological populations over successive generations.
Life is characterized by the ability to self-replicate, facilitated by biomolecules like nucleic acids and proteins.
Membranes create compartments that separate life processes from the environment, essential for cellular function.
The four main biomolecules supporting life are lipids, carbohydrates, nucleic acids, and proteins.