Chapter 14/15 Vocab

genome

The complete set of an organism's genetic material, including all of its genes and non-coding sequences of DNA.

nucleotide

The building blocks of nucleic acids (DNA and RNA), consisting of a sugar molecule, a phosphate group, and a nitrogenous base.

nucleic acid

A class of macromolecules that includes DNA and RNA. They are involved in the storage and transmission of genetic information.

nitrogenous base

The chemical bases adenine (A), cytosine (C), guanine (G), thymine (T), and uracil (U) that make up the building blocks of DNA and RNA.

DNA

The molecule that carries genetic information in cells. It consists of a double helix made up of four nucleotide bases: adenine (A), thymine (T), cytosine (C), and guanine (G).

RNA

A molecule similar to DNA that plays a central role in various biological processes, including protein synthesis.

complementary base pair

In DNA and RNA, the specific pairing between adenine (A) and thymine (T) or uracil (U), and between cytosine (C) and guanine (G). These base pairs are critical for maintaining the double-stranded structure of DNA and RNA.

hydrogen bonds

Weak chemical bonds formed between hydrogen atoms and other atoms (usually oxygen or nitrogen). In DNA, hydrogen bonds help hold the complementary base pairs together.

3’

The 3' end of a nucleic acid strand, typically referring to DNA or RNA, is the end where the carbon in the deoxyribose (in DNA) or ribose (in RNA) sugar is attached to the third carbon of the adjacent nucleotide.

5’

The 5' end of a nucleic acid strand, typically referring to DNA or RNA, is the end where the carbon in the deoxyribose (in DNA) or ribose (in RNA) sugar is attached to the fifth carbon of the adjacent nucleotide.

antiparallel

A term used to describe the orientation of the two strands in a DNA double helix. The strands run in opposite directions, with one strand oriented in the 5' to 3' direction and the other in the 3' to 5' direction.

DNA replication

The process by which a cell makes an identical copy of its DNA. It is essential for cell division and the transmission of genetic information to offspring.

DNA polymerase

An enzyme responsible for synthesizing DNA from a DNA template during replication.

template

In the context of DNA replication and transcription, the DNA strand that serves as a guide for the synthesis of a complementary strand of RNA or DNA.

semiconservative

A term used to describe the process of DNA replication, where each new DNA molecule contains one original strand and one newly synthesized strand.

transcription

The process of synthesizing RNA from a DNA template. It is a key step in gene expression.

RNA polymerase

An enzyme responsible for synthesizing RNA from a DNA template during transcription.

gene

A segment of DNA that contains the instructions for making a specific protein or set of proteins. Genes are the fundamental units of heredity.

promoter

A region of DNA that serves as the binding site for RNA polymerase and initiates transcription of a specific gene.

terminator

In transcription, a specific DNA sequence that signals the end of gene transcription.

mRNA

A type of RNA molecule that carries the genetic information from DNA to the ribosome, where it is used as a template for protein synthesis.

spliced/splitting

The process of removing introns (non-coding regions) from pre-mRNA and joining together the exons (coding regions) to form mature mRNA before it is translated into protein.

translation

The process by which the genetic information in mRNA is used to assemble amino acids into a polypeptide chain during protein synthesis.

ribosome

A cellular organelle responsible for protein synthesis. It reads the mRNA and assembles amino acids into polypeptide chains.

rRNA

A type of RNA that is a structural component of ribosomes and plays a key role in protein synthesis.

codon

A sequence of three nucleotides in messenger RNA (mRNA) that specifies a particular amino acid or serves as a start or stop signal for protein synthesis.

start codon

The specific codon (AUG) that signals the beginning of protein synthesis and the incorporation of the first amino acid in the polypeptide chain.

stop codon

Also known as termination codon, it is one of three codons (UAA, UAG, and UGA) that signals the end of protein synthesis, causing the release of the polypeptide chain from the ribosome.

tRNA

A type of RNA molecule that carries amino acids to the ribosome during protein synthesis and matches them to the appropriate codons on the mRNA.

anticodon

A sequence of three nucleotides on transfer RNA (tRNA) that is complementary to a specific codon on messenger RNA (mRNA). It helps to bring the correct amino acid during protein synthesis.

amino acid

A building block of proteins. Amino acids are linked together in a specific sequence to form polypeptide chains, which then fold into functional proteins.

polypeptide

A chain of amino acids linked together by peptide bonds. Polypeptides are the precursors to proteins.

protein

one or more polypeptide chains folded into a functional structure.  Proteins perform most functions within cells.

reading frame

The specific grouping of nucleotides in a sequence of DNA or RNA that is read during protein synthesis. It determines how the sequence is translated into amino acids.

genetic code

The set of rules that determines how the nucleotide sequence of DNA or RNA is translated into the amino acid sequence of a protein during protein synthesis.

initiation

In the context of protein synthesis (translation), it is the first step where the ribosome assembles on the mRNA and the process begins.

elongation

In the context of protein synthesis (translation), it refers to the stage where amino acids are added to the growing polypeptide chain according to the information in the mRNA.

termination

The final stage in both transcription and translation, where the process is concluded, and the newly synthesized molecule (RNA or protein) is released.

mutation

A change in the DNA sequence of an organism's genome. Mutations can be harmful, beneficial, or have no effect on an organism.

point mutation

A type of mutation that involves a change in a single nucleotide base pair in a DNA or RNA sequence.

missense mutation

A type of point mutation where a single nucleotide change in the DNA sequence results in the substitution of one amino acid with another in the protein.

nonsense mutation

A type of point mutation where a single nucleotide change in the DNA sequence creates a premature stop codon, resulting in the termination of protein synthesis and often a non-functional protein.

silent mutation

A type of point mutation where a single nucleotide change in the DNA sequence does not result in any change in the amino acid sequence of the protein.

insertion

A type of mutation where one or more nucleotide bases are added to a DNA, causing a shift in the reading frame and potentially leading to significant changes in the resulting protein.

deletion

A type of mutation where one or more nucleotide bases are removed from a DNA, causing a shift in the reading frame and potentially leading to significant changes in the resulting protein.

wobble position

The third position in a codon (mRNA) that can tolerate some variation in the base pairing rules, allowing for greater flexibility in the genetic code and the use of multiple codons for the same amino acid.

redundant

Refers to the property of the genetic code where multiple codons can code for the same amino acid. This redundancy helps protect against errors in protein synthesis.

genetic variation

The diversity in the genetic makeup of individuals within a population or species. It is the raw material for evolution.

natural selection

The process by which organisms with advantageous traits are more likely to survive and reproduce, leading to the gradual evolution of populations over time.

evolution

The process by which species change over time through the accumulation of genetic variations, leading to the development of new species. It is driven by mechanisms like natural selection and genetic drift.