Unit 1 section A

Water. DNA. RNA. Origins of Life.

Hydrogen Bonds

A weak bond of attraction between a hydrogen atom and another atom

Polar covalent bond

when atoms with different electronegativities share electrons unequally in a covalent bond

Cohesion

Attraction between molecules of the same substance

Adhesion

An attraction between molecules of different substances

Solvent

A liquid substance capable of dissolving other substances

Metabolism

The combination of chemical reactions through which an organism builds up or breaks down materials

Xylem

Nonliving vascular tissue that carries water and dissolved minerals from the roots of a plant to its leaves

Surface tension

The force that acts on the surface of a liquid to minimize the area of the surface

Capillary action

The ascension of liquids through a slim tube due to adhesive and cohesive forces interacting between the liquid and the surface

Hydrophobic

Having an aversion to water; tending to coalesce and form droplets in water.

Hydrophilic

A molecule that is able to interact with water

Buoyancy

The ability of a fluid to exert an upward force on an object placed in it

Viscosity

A liquid's resistance to flowing

Thermal conductivity

The rate at which a substance transfers heat

Specific heat capacity

The amount of heat one gram of a substance must absorb or lose to change its temperature by one degree Celsius

Apoplast pathway

A route that water takes through a plant root to the xylem through cell walls.

Extraplanetary

Situated or originating outside the region of the planetary orbits

Goldilocks zone

habitable zone able to sustain life (has the necessities for organisms to live, grow, and reproduce)

Extraterrestrial

out of this world; above and beyond what is found on planet Earth

Asteroid

any of numerous small celestial bodies composed of rock and metal that move around the sun

Exoplanet

a planet-like body that orbits a star other than the sun outside of our solar system

Comet

A loose collection of ice and dust that orbits the sun, typically in a long, narrow orbit.

Frost line

the boundary in the solar nebula beyond which ices could condense; only metals and rocks could condense within the frost line

Genetics

the study of how genes and how traits are passed down

DNA

A complex molecule containing the genetic information that makes up the chromosomes

RNA

A single-stranded nucleic acid that passes along genetic messages

Nucleotide

Basic units of DNA molecule, composed of a sugar, a phosphate, and one of 4 DNA bases

Phosphate Group

A functional group consisting of a phosphorus atom covalently bonded to four oxygen atoms

Deoxyribose

A five-carbon sugar that is a component of DNA nucleotides

Ribose

A five-carbon sugar found in RNA

Nitrogen base

carbon ring structure found in DNA or RNA that contains one or more atoms of nitrogen

What consists of a nitrogen base?

adenine, guanine, cytosine, thymine, and uracil

Genetic code

the ordering of nucleotides in DNA molecules that carries the genetic information in living cells

Polymer

A long molecule consisting of many similar or identical monomers linked together.

Monomer

a molecule that can be bonded to other identical molecules to form a polymer.

Condensation reaction

monomers join to form polymers and water molecules are formed as a result

Complementary base pairs

Hydrogen bonding between particular pyrimidines and purines. Adenine & Thymine. Cytosine & Guanine.

What is the complementary base pair of Adenine?

Thymine

What is the complementary base pair of guanine?

Cytosine

What is the complementary base pair of thymine?

Adenine

What is the complementary base pair of cytosine?

Guanine

Polynucleotides

A polymer consisting of many nucleotide monomers in a chain; nucleotides can be those of DNA or RNA.

Endotherm

A polymer consisting of many nucleotide monomers in a chain; nucleotides can be those of DNA or RNA.

Antiparallel

The opposite arrangement of the sugar-phosphate backbones in a DNA double helix.

DNA replication

The process in which DNA makes a duplicate copy of itself.

Gene expression

The process by which a gene produces its product and the product carries out its function

Virus

A tiny, nonliving particle that invades and then reproduces inside a living cell.

Homeostasis

relatively constant internal physical and chemical conditions that organisms maintain

Metabolism

the combination of chemical reactions through which an organism builds up or breaks down materials

Purine definition

a nitrogenous base that has a double-ring structure; one of the two general categories of nitrogenous bases found in DNA and RNA

What nucleotide bases are purine?

Adenine and Guanine

Pyrimidines

The nucleotide bases present in DNA and RNA

What nucleotide bases are pyrimidine?

Cytosine, Uracil, and Thymine

What are the pyrimidines in RNA?

cytosine and uracil

What pyrimidine is only found in DNA?

Thymine

Guanine

Adenine

Cytosine

Thymine