DNA - The Code Of Life Flashcards
DNA
Deoxyribonucleic Acid; made up of monomers called nucleotides with the nitrogenous bases cytosine, guanine, adenine and thymine; it carries the genetic code for protein synthesis
RNA
Ribonucleic Acid; there are three types of RNA viz. messenger RNA(mRNA), transfer RNA(tRNA) and ribosomal RNA(rRNA) each of which play particular roles in protein synthesis
Protein synthesis
Process by which amino acids are linked together in a particular sequence to form a required protein
Chromosome
String-like structure found in the nucleus of dividing cells; formed from chromatin network; contains the hereditary material DNA
Nuclear membrane
Membrane surrounding the nucleus
Chromatid
Half a chromosome; the 2 halves are held together bya centromere; these 2 halves have actually been formed from one chromosome by DNA replication
Chromatin network
An entangled mass of threads found in the nucleus of cells which are in the “resting stage” I.e. cells which are not dividing; they give rise to chromosomes
Nucleolus
Structure in the nucleus in which ribosomal RNA (rRNA) is synthesised
Nucleotide
The monster which forms DNA and RNA; each nucleotide is made up of a sugar, a phosphate ion and a nitrogenous base
Nuclear DNA
DNA found within the nucleus of cells; is made up of genetic material from both parents
Extra-nuclear DNA
DNA that is located outside of the nucleus such as mitochondrial DNA in the mitochondria
Mutation
Sudden, random changes in the genetic code of an organism which can be inherited
Deoxyribose
The sugar that is a part of the DNA molecule
Complementary base pairs
Nitrogenous bases that always pair with each other and are joined by hydrogen bonds in a DNA molecule
Adenine - Thymine/Urasil
Cytosine - Gaunine
Double helix
The shape of the DNA molecule consisting of two strands joined to each other and which are spiraled twisted
Adenine
One if four nitrogenous bases found in DNA and RNA; it DNA it always joins with thymine
Thymine
One of the four nitrogenous bases found in DNA; not found in RNA; always joins with adenine
Cytosine
One of the four nitrogenous bases found in DNA and RNA; always joins with guanine in DNA
Guanine
One of the four nitrogenous bases found in DNA and RNA; always joins with cytosine in DNA
Weak hydrogen bonds
Bonds holding nitrogen bases together in DNA
Gene
A small portion of DNA which carries the genetic code for the formation of a particular trait or characteristic; it also carries the code for proteins
Non-coding DNA
Portions of DNA that do not code for specific amino acids
Cell cycle
A series of events that occur during the life span of the cell
Mitosis
A type of cell division which results in two cells which are genetically identical to each other and to the parent cell (which no longer exists)
Meiosis
A type of cell division where the nucleus divides twice but the chromosomes duplicate once only, resulting in four cells each with half the number of chromosomes as the original
DNA replication
Process by which two identical DNA molecules are formed from one DNA molecule; occurs just before cell division
Interphase
The stage in mitosis and meiosis during which DNA replication takes place; since most of the cells life is spent in this stage, it was originally thought to be a resting stage that occurred between mitotic and meiotic divisions
Template
Strand of DNA upon which another strand of DNA is built during replication or mRNA is built during protein synthesis
Complementary strand
The new DNA strand that developed during DNA replication according to the template strand of DNA, using free DNA nucleotides
Fingerprints
Imprint of the pattern on a finger that us unique to all individuals except identical twins
DNA ‘fingerprint’
The unique pattern formed by the DNA fragments of an individual; the use of the term DNA profile is preferred to avoid confusion with normal fingerprints
DNA profiling
The process by which DNA ‘fingerprint’/DNA profile of an individual is obtained
Inherited disorder
A disorder that can be passed on from one generation to the next since it is controlled by a particular gene
Forensic science
The application of a broad spectrum of sciences and technologies to investigate and establish facts of interest in relation to criminal or civil law
Amino acids
The monomers which serve as building blocks for the synthesis of proteins, made up of an amino acid group (NH²) and carboxylic acid group
Protein
A complex organic compound made up of a long chain of amino acids; a typical amino acid has approximately 300 amino acids; enzymes and hormones are specialized proteins
Dipeptide
Molecule consisting of two amino acids linked by a peptide bond
Polypeptide
A long chain of amino acids linked together by peptide bonds
Dehydration synthesis
A process by which small molecules combine to form longer ones with water being released during the process
Nucleus
The structure in a cell that contains the chromosomes. The nucleus has a membrane around it, and is where RNA is made from the DNA in the chromosomes.
Nuclear pore
Opening in the nuclear membrane that allows for the passage of mRNA into the cytoplasm
Transcription
Synthesis of mRNA from DNA, by complementary matching of the nitrogenous bases in DNA
Translation
Part of protein synthesis involving the combination of amino acids according to the colons on mRNA
Codon
A sequence of three consecutive bases found in DNA or mRNA onto which fit three complementary bases of tRNA during protein synthesis
Anticodon
Sequence of three consecutive bases on tRNA which complement the bases on the codon found in mRNA
mRNA
Messenger RNA; takes information for protein synthesis from the nucleus to the ribosome
tRNA
Transfer RNA; the RNA which carries amino acids and arranges itself on the mRNA according to the arrangement of bases on mRNA, with the pairing of complementary bases
Ribosome
A small grain-like structure found in the cytoplasm or cytosol of plant and animal cells, which are the actual sites of protein synthesis
