Biology terms

• what are enzymes, and what is their monomer?

  Proteins, amino acids
• what does CRISPR stand for

  Clustered Regular Interspaced Short Palindromic Repeats
• what's a restriction endonuclease

  An endonuclease that cuts DNA at a specific recognition site
• what is a peptide and what is a polypeptide chain?

  a molecule containing two or more amino acids, a continued chain of amino acids and its another name for protein
• what is transcription?

  when a sequence of DNA is used to produce a complementary sequence of premature mRNA
• what is translation?

  where mRNA sequence is used to produce a corresponding amino acid sequence to build a polypeptide
• what is RNA processing?

  modifying the pre-mRNA molecule into an mRNA molecule that can be used on translation
• what are the steps in transcription?

  initiation, elongation and termination
• how are proteins made?

  condensation reaction- where two smaller molecules combine to form a polymer and water is produced
• what are the protein structures?

  Primary, secondary, tertiary, quaternary
• what is the primary structure of a protein?

  the sequence of amino acids that are linked together by peptide bonds to form polypeptide chains which is determined by the genetic code contained in DNA
• what is the secondary structure of a protein?

  the folding and coiling of a section within a polypeptide chain, which is determined by hydrogen bonds between neighbouring CO and NH groups of different amino acids
• what are the structures that can be formed in the secondary structure?

  alpha helices - coiled or spiral arrangement. beta pleated sheets - directionally oriented staggers strand conformation. random coils
• what is the tertiary structure of a protein?

  overall 3D shape of the protein, how alpha helices / beta sheets and random coils fold in respect of each other, stabilised by hydrogen bonds between R group and stronger disulphide bridges between cysteine amino acids.
• what is the quaternary structure of a protein?

  when 2 or more polypeptide chains combine to form a protein, but not all proteins have quaternary structure
• what are the most common colours used for amino acids?

  black for carbon, red for oxygen, blue for nitrogen, white for hydrogen, yellow for sulphur, orange for phosphorous
• what is complementary base pairing?

  when nucleotides bond together they form a polynucleotide chain, C and G join together with 3 hydrogen bonds, A and T join together with 2 hydrogen bonds
• the genetic code?

  genes are made of 3 nucleotides that codes for one amino acid called triplets. when transcribed into an mRNA molecule its known as a condon
• what are the different components of a gene?

  promoter region, introns and exons, termination sequences and operator regions (typically found in prokaryotes)
• what is the promoter region?

  upstream binding region for the enzyme that is involved in the encoding process which is RNA polymerase
• what are introns and exons?

  introns are regions of DNA that are non coding segments and are spliced out of the mRNA during RNA processing, exons are regions of DNA that are expressed as protein or RNA
• start and stop codons?

  a start triplet is where the gene will begin (AUG) and the stop codon (termination sequence) is where the gene will end (UAA, UAG, UGA)
• what is RNA processing / post transcriptional modifying?

  Addition of 5' methyl cap and poly A tail on 3' end, splicing of introns and sometimes exons which allows for different sequences to be produced (alternative splicing)
• what is alternative splicing of pre mRNA?

  human genome has 25000 genes but more than 25000 proteins. one gene can be regulated in different ways to produce more than one type of protein. -different proteins at different stages of life. - alternative splicing of pre mRNA is the cutting and rejoining of exons
• what happens in translation?

  mRNA travels to a ribosome and initiation occurs, followed by elongation then termination
• what is initiation in translation?

  the small ribosomal subunit attached to 5' end of mRNA and reads it until it reaches the start codon. tRNA (transfer RNA) with the complementary anti codon binds to the ribosome and delivers the amino acid (met). large ribosomal subunit attaches to mRNA for translation
• arabinose is a protein that makes plasmids glow under a UV light
• what is meant by ‘non-pathogenic strain of recombinant E.coli?

  The E.coli strain is unable to cause disease and contains foreign DNA.
• what is CRISPR Cas9?

  a defence mechanism for bacteria against viruses, its an adaptive immune system because it remembers viruses DNA sequence
• what is bacteriophage?

  its a virus that infects bacteria
• what are the two stages of photosynthesis?

  light dependent and light independent
• what is malate in plants?

  or malic acid, an organic 4 carbon acid with the formula C4H6O5
• what is the difference between C3, C4 and CAM photosynthesis?

  C3 plants use normal photosynthesis, C4 keep their stomata open during the day whereas CAM plants keep the stomata closed during the day
• Which type of plant uses the least amount of energy to undertake photosynthesis?

  C3 plants
• State the location of the light-dependent reactions in CAM photosynthesis?

  thylakoid membrane or grana
• Identify two outputs of the light-dependent reactions of CAM photosynthesis?

  oxygen and ATP
• CAM plants put energy into conserving water. Why don’t CAM plants conserve water by reducing the number of water molecules used for an input of photosynthesis?

  water molecules are required for photosynthesis as inputs and because photosynthesis is important for plants to grow, CAM plants can't sacrifice photosynthesis rates to save a few water molecules
• what are the inputs and outputs in photosynthesis?

  light dependent input is water and the output is oxygen

  light independent input is carbon dioxide and the outputs are glucose and water
• what do inhibitors do?


  the regulate the reaction of processes by blocking the active and non active sites of an enzyme needed for the reaction, they help in not wasting energy to process things we don't need, and some things that are toxic at high levels