Bio 171 Lecture 1: Characteristics of life, genetic material, 3 domains, and the tree of life

Vocabulary flashcards covering key terms related to life characteristics, genetic material, the three domains of life, and the tree of life as presented in Bio 171 Lecture 1.

amino acid

The building blocks of proteins; small organic molecules that link together to form polypeptides.

anti-codon

A three-nucleotide sequence on tRNA that base-pairs with a complementary codon on mRNA during translation.

Archaea

One of the three domains of life; contains prokaryotic organisms genetically distinct from Bacteria and Eukarya.

Bacteria

One of the three domains of life; prokaryotic microorganisms lacking a membrane-bound nucleus.

carbohydrate

An organic molecule (sugar, starch, etc.) used by cells for energy and structural roles.

cell membrane

A phospholipid bilayer surrounding the cell that controls the movement of substances in and out.

central dogma

The flow of genetic information: DNA is transcribed into RNA, which is translated into protein.

codon

A three-nucleotide sequence in mRNA that specifies a particular amino acid or a stop signal.

DNA

Deoxyribonucleic acid; the genetic material of organisms, usually double-stranded and stores genetic information.

DNA replication

The process of copying DNA, where strands separate and new complementary strands are synthesized.

Eukarya

Domain containing all eukaryotic organisms (plants, animals, fungi, protists).

eukaryote

An organism whose cells contain a nucleus and other membrane-bound organelles.

gene

A stretch of nucleotides that contains a sequence used to make RNA and/or protein and is active when expressed.

gene expression

Process by which information from a gene is used to produce a functional product (RNA and/or protein).

genetic code

The set of codon-to-amino-acid mappings that defines how mRNA codons are translated into proteins.

mRNA

Messenger RNA; carries the genetic code from DNA to the ribosome for protein synthesis.

MRCA (most recent common ancestor)

The most recent ancestor from which two or more lineages are descended.

non-template DNA

The DNA strand not used as the template for transcription; also called the coding/sense strand.

nucleic acid

Any RNA or DNA molecule; the polymer that stores and transmits genetic information.

nucleus

Membrane-bound organelle in eukaryotic cells that houses the cell’s DNA.

peptide bond

A covalent bond linking amino acids together in a protein.

phospholipid

A lipid with a phosphate group; a primary component of cell membranes forming a bilayer.

phylogenetic tree

A diagram showing evolutionary relationships among species or groups.

prokaryote

Organism without a true nucleus; includes Bacteria and Archaea.

protein

A large, functional molecule made of amino acids that performs a wide range of cellular roles.

rRNA

Ribosomal RNA; a component of ribosomes that plays a catalytic and structural role in translation.

RNA

Ribonucleic acid; single-stranded or functional RNA molecules involved in coding, decoding, regulation, and expression of genes.

Ribosome

Molecular machine composed of rRNA and proteins that translates mRNA into protein.

tRNA

Transfer RNA; delivers specific amino acids to the ribosome during translation and contains an anticodon.

template DNA

The DNA strand used as the template for transcription; complementary to the coding strand.

tree of life

A comprehensive phylogenetic tree showing the evolutionary relationships among all living organisms.

transcription

The process of copying a DNA sequence into a complementary RNA sequence, usually by RNA polymerase.

translation

The process by which ribosomes synthesize proteins from an mRNA template, using tRNA and codons.

Metabolize

An organism’s ability to take in energy and material from the environment