Unit 3 List 1 DNA & Heredity

Question 1

Adenine

Answer 1

A chemical compound that is used to make one of the building blocks of DNA and RNA

Question 2

Amino acid

Answer 2

molecules that combine to form proteins

Question 3

Anticodon

Answer 3

a trinucleotide sequence located at one end of a transfer RNA (tRNA) molecule, which is complementary to a corresponding codon in a messenger RNA (mRNA) sequence

Question 4

Cell types

Answer 4

eukaryotic cells, which possess a nucleus, and prokaryotic cells, which lack a nucleus but have a nucleoid region

Question 5

Cell differentiation

Answer 5

the process in which a stem cell changes from one type to a differentiated one

Question 6

Chromosome

Answer 6

A structure found inside the nucleus of a cell. A chromosome is made up of proteins and DNA organized into genes. Each cell normally contains 23 pairs of chromosomes.

Question 7

Codon

Answer 7

a three-letter genetic sequence found in both DNA and RNA. It codes for a specific amino acid, or start and stop signals, for the protein synthesis process.

Question 8

Cytoplasm

Answer 8

the gelatinous liquid that fills the inside of a cell. It is composed of water, salts, and various organic molecules.

Question 9

Cytosine

Answer 9

forming base pairs by bonding with guanine and forming the genetic code found in both DNA and RNA

Question 10

Deoxyribose

Answer 10

a pentose (5-carbon sugar) biological molecule. Deoxyribose sugar, along with phosphate, makes up the sugar-phosphate backbone in deoxyribonucleic acid

Question 11

DNA

Answer 11

the molecule that carries genetic information for the development and functioning of an organism

Question 12

Double helix

Answer 12

a term used to describe the physical structure of DNA. A DNA molecule is made up of two linked strands that wind around each other to resemble a twisted ladder in a helix-like shape

Question 13

Endoplasmic reticulum

Answer 13

a network of membranes inside a cell through which proteins and other molecules move

Question 14

Enzyme

Answer 14

proteins that help speed up metabolism, or the chemical reactions in our bodies. They build some substances and break others down

Question 15

Gene

Answer 15

The basic unit of heredity passed from parent to child. Genes are made up of sequences of DNA and are arranged, one after another, at specific locations on chromosomes in the nucleus of cells.

Question 16

Golgi apparatus

Answer 16

cell organelle that helps process and package proteins and lipid molecules, especially proteins destined to be exported from the cell.

Question 17

Guanine

Answer 17

A purine nucleobase that complementary pairs with cytosine in DNA and RNA,

Question 18

Hydrogen bond

Answer 18

an attraction between two atoms that already participate in other chemical bonds. One of the atoms is hydrogen, while the other may be any electronegative atom, such as oxygen, chlorine, or fluorine

Question 19

mRNA

Answer 19

Messenger RNA molecules carry the genetic information needed to make proteins. They carry the information from the DNA in the nucleus of the cell to the cytoplasm where the proteins are made

Question 20

Mutation

Answer 20

A change in the usual DNA sequence at a particular gene locus. Although the term often has a negative connotation, mutations (including polymorphisms) can be harmful, beneficial, or neutral in their effect on cell function.

Question 21

Nitrogenous base

Answer 21

A molecule that contains nitrogen and has the chemical properties of a base

Question 22

Nuclear membrane

Answer 22

a double layer that encloses the cell’s nucleus, where the chromosomes reside. The nuclear membrane serves to separate the chromosomes from the cell’s cytoplasm and other contents.

Question 23

Nucleic acid

Answer 23

large biomolecules that play essential roles in all cells and viruses. A major function of nucleic acids involves the storage and expression of genomic information

Question 24

Nucleotide

Answer 24

the basic building block of nucleic acids (RNA and DNA). A nucleotide consists of a sugar molecule (either ribose in RNA or deoxyribose in DNA) attached to a phosphate group and a nitrogen-containing base.

Question 25

Nucleus

Answer 25

the membrane-enclosed organelle within a cell that contains the chromosomes. An array of holes, or pores, in the nuclear membrane allows for the selective passage of certain molecules (such as proteins and nucleic acids) into and out of the nucleus.

Question 26

Peptide bond

Answer 26

links these amino acids together to form a protein. A peptide bond is a covalent bond formed as 2 amino acids are joined together through dehydration synthesis, a process in which a water molecule is removed as a byproduct to link monomers together.

Question 27

Phosphate group

Answer 27

a phosphorus atom bound to four oxygen atoms, but it has many important roles. Along with sugars and bases, it makes up nucleic acids, like DNA and RNA. As part of energy carriers, like ATP, it provides energy for moving our muscles.

Question 28

Polypeptides

Answer 28

a continuous, unbranched chain of amino acids joined by peptide bonds. To generate an amide, the peptide bond connects the carboxyl group of one amino acid to the amine group of the next amino acid.

Question 29

Protein synthesis

Answer 29

the process that cells use to create proteins

Question 30

Ribose

Answer 30

an organic compound classified as a monosaccharide, or simple sugar. Ribose is composed of five carbon atoms, ten hydrogen atoms, and five oxygen atoms that have been bonded together. Ribose is a pentose sugar.

Question 31

Ribosome

Answer 31

the cellular machinery responsible for making proteins. There are many ribosomes in each cell, each made up of two subunits. These two subunits lock around the messenger RNA and then travel along the length of the messenger RNA molecule reading each three-letter codon.

Question 32

RNA

Answer 32

a nucleic acid present in all living cells that has structural similarities to DNA. Unlike DNA, however, RNA is most often single-stranded.

Question 33

rRNA

Answer 33

part of the ribosome, or protein builders, of the cell. Ribosomes are responsible for translation, or the process our cells use to make proteins. rRNA are responsible for reading the order of amino acids and linking amino acids together

Question 34

Start codon

Answer 34

the first codon of a messenger RNA (mRNA) transcript translated by a ribosome. The start codon always codes for methionine in eukaryotes and archaea and a N-formylmethionine (fMet) in bacteria, mitochondria and plastids.

Question 35

Stop codon

Answer 35

a sequence of three nucleotides (a trinucleotide) in DNA or messenger RNA (mRNA) that signals a halt to protein synthesis in the cell.

Question 36

Thymine

Answer 36

a pyrimidine, which means that it is composed of a single ring consisting of 4 carbon atoms and 2 nitrogen atoms. Thymine helps stabilize nucleic acid structures

Question 37

Transcription

Answer 37

the process by which a cell makes an RNA copy of a piece of DNA. This RNA copy, called messenger RNA (mRNA), carries the genetic information needed to make proteins in a cell.

Question 38

Translation

Answer 38

the process by which a cell makes proteins using the genetic information carried in messenger RNA (mRNA). The mRNA is made by copying DNA, and the information it carries tells the cell how to link amino acids together to form proteins.

Question 39

tRNA

Answer 39

a small RNA molecule that plays a key role in protein synthesis. Transfer RNA serves as a link (or adaptor) between the messenger RNA (mRNA) molecule and the growing chain of amino acids that make up a protein.

Question 40

Uracil

Answer 40

a nitrogenous base that is a component of RNA. It is used by RNA during the processes of transcription and translation within cells. These processes read the genetic code from DNA and instruct the cell on how to make proteins. It has a single ring structure and bonds freely with adenine.

Question 41

Vesicle

Answer 41

a structure within or outside a cell, consisting of liquid or cytoplasm enclosed by a lipid bilayer. Vesicles form naturally during the processes of secretion (exocytosis), uptake (endocytosis), and the transport of materials within the plasma membrane.