Large molecule that carries LOTS of information. In exam questions ATP properties are frequently compared to glucose, to emphasise why ATP is the immediate source of energy for cells rather than glucose. The DNA polymer occurs in pairs, and these pairs are joined together by hydrogen bonds between the bases. The monomer units in nucleic acids are called nucleotides. ATP is made from ADP, adenosine diphosphate, by the addition of an inorganic phosphate via a condensation reaction and using the enzyme ATP synthase. These bases pair in the centre of the molecule by means of hydrogen bonds. OCR (A) A-Level Biology We have worked hard to compile every past paper by topic and exam board! Written by renowned author Neil Roberts, this Illuminate Science Study Guide for the OCR A Level Biology Year 1 & AS is ideal for studying on the go. These random … Below is a diagram of ATP, and this is the level of detail that you need to remember the structure in. Resources. • Answer . The following outlines the topics and exam structure. Pentose Sugar 2. These two separated strands both act as templates for DNA replication. Multiple Choice Questions (MCQ) topic quiz - answers. The Okazaki fragments are later joined together by the enzyme DNA ligase. 1. 12th grade. 5. This is explained and demonstrated in the five points below. 35%. Enzyme that makes the phosphodiester bond between the nucleotides in semi-conservative replication. ATP, or Adenosine Tri Phosphate, is an immediate source of energy for biological processes. Edit. Time allowed: 2 hours 15 minutes . Meselson and Stahl performed the experiment below to prove this. ... nucleotides & ATP Calcium ions regulate protein channels, impulse transmission You still gain credit for answering correctly on the seond attempt. The tRNA molecule with the complementary anticodon to the AUG codon aligns opposite the mRNA, held in place by the ribosome. If three bases coded for one amino acid this would allow for 64 amino acids to be coded for (4 x 4 x 4 combinations of code). Each amino acid is coded for by a sequence of 3 bases in a gene. reviews. In order for new cells to be created all the DNA in a cell must be replicated first, to ensure that when the cell splits in half each new cell still contains the full amount of DNA. Free mRNA nucleotides align opposite exposed complementary DNA bases. This is relevant, as an enzyme that catalyses DNA replication is complementary in shape to the 3’ end, and can therefore only attach to the DNA at this location. ATP can enable phosphorylation, making other compounds more reactive. ATP can’t pass out of the cell, the cell always has an immediate supply of energy. Communicable Diseases, Disease Prevention and the Immune System, Practical Skills Assessed in the Practical Endorsement, Practical Skills Assessed in a Written Examination, Cell Division, Cell Diversity and Cellular Organisation, Development of Practical Skills in Biology, Stable structure due to sugar-phosphate backbone (covalent bonds) and the double helix, Double stranded so replication can occur using one strand as a template. DNA contains the base thymine, whereas RNA contains uracil instead. Biological mathematics and problem-solving skills can be fully integrated into teaching and learning. Weak hydrogen bonds for easy unzipping of the two strands in a double helix during replication. Close. It is made during transcription in the nucleus. Deoxyribonucleic Acid (DNA) codes for the sequence of amino acids in the primary structure of a protein, which in turn determines the final 3D structure and function of a protein. Nitrogenous base 3. The production of proteins from the DNA code within DNA occurs in two main stages: Transcription – where the DNA code for one gene is copied into mRNA. The letters not in boxes represent normal DNA nucleotides. This is describing the strong covalent bonds between the sugar and phosphate groups that hold the polymer together. … This methionine is later removed from the protein if it is not actually needed for the structure. Glucose would need several bonds to be broken down to release all its energy. Designed by the teachers at SAVE MY EXAMS for the CIE A Level Biology 2019-21 (9700) syllabus. DNA helicase breaks the hydrogen bonds between bases. Phosphate Group/s The pentose sugar is the main component to which the nitrogenous base and the phosphate groups are attached. Which maths skills you need to practise for the new specification A-level Biology - excellent resources from OCR - also applies to AQA and Eduqas, lots of great practice questions The quantity of maths in the 2017 specification is a challenge to many students - so I put together a summary of all of the OCR A new … What percentage would be uracil? Learn vocabulary, terms, and more with flashcards, games, and other study tools. Each quiz consists of 12 questions and you have ten minutes to complete the quiz. Nucleic Acids A-level OCR DRAFT. DNA is much larger because it contains approximately 23,000 genes (the entire genome), whereas RNA is much shorter because it is only the length of one gene. DNA is too large to leave the nucleus and would be at risk of being damaged by enzymes, therefore destroying the genetic code permanently. … Subject: Science Biology. They consist of a pentose sugar (deoxyribose/ribose) a phosphate group and a nitrogenous base that is either a pyrimidine or a purine. RNA has the base uracil instead of thymine. 64 combinations is more than is needed to code for 20 amino acids, and as a result each amino acid is actually coded for by more than one triplet of bases. Start studying OCR A A LEVEL BIOLOGY - NUCLEIC ACIDS. This means that all cells have a constant supply of ATP or ADP +Pi, but a cell can run out of glucose. This is insufficient to code for 20 amino acids. Complementary base pairing allows identical copies to be made. You may use an HB pencil for graphs and diagrams. all . • Flash cards summarise all the … This number refers to which carbon within the deoxyribose sugar of the nucleotide is closest to the top/bottom – see diagram below. Home > A Level and IB study tools > Biology > OCR Biology A Module 2 Flashcards. ... OCR A level Biology … mRNA is created in the nucleus and it then leaves the nucleus to carry the copy of the genetic code of one gene to a ribosome in the cytoplasm. This cloverleaf shape is held in place by hydrogen bonds, demonstrated with the dashed lines in the diagram below. All the DNA newly synthesised will now be lighter. Enter an answer in the box! ATP is not only able to release energy to the surroundings, it can also transfer energy to different compounds. At the end of every gene there are 3 bases that do no code for an amino acid and is none as a ‘stop codon’. Proteins are made from amino acids. Like with DNA replication, this unwinding and unzipping is catalysesd by DNA helicase. DNA Polymerase. Nucleic acids come in two forms: DNA (deoxyribonucleic acid) and RNA (ribonucleic acid). The same triplet of bases codes for the same amino acid in all organisms, this is why the genetic code is described as being universal. Module 2: Foundations in Biology. H bonds between base pairs hold the shape. These, combined with the Practical Endorsement, constitute the full A Level. There are 20 amino acids that the genetic code has to be able to code for. tRNA molecules are found in the cytoplasm and have amino acids attached to them. This is your chance to try it out for yourself – the topics Cell structure, Biological molecules, and Nucleotides and nucleic acids are available FREE! When describing the DNA double helix, the top and bottom of each strand is described as either the 3’ (prime) end or the 5’ (prime) end. Each tRNA molecule has an anticodon which is complementary to the codons on mRNA. Before the DNA can be copied the double helix must first unwind. The enzyme DNA polymerase is responsible for then forming the phosphodiester bond between these nucleotides to create a new polymer chain of DNA. Exons are the sections of DNA that do code for amino acids. 54% average accuracy. It is created via condensation reactions between the deoxyribose sugar and the phosphate group, creating a phosphodiester bond. Nucleotides and Nucleic Acids ATP. Start quiz. The chains are always the same distance apart because the bases pair up in a specific way. Free-floating [blank_start]DNA Nucleotides[blank_end] are attracted to the now-exposed bases and form Hydrogen Bonds with their [blank_start]Complementary Base Pair[blank_end]. However, some mutations result in the creation of a protein that provides an advantage to an organism. [blank_start]DNA Polymerase[blank_end] catalyses [blank_start]Condensation[blank_end] Reactions to form [blank_start]Phosphodiester Bonds[blank_end] between the new Nucleotides … a Phosphate Group. It is made up of deoxyribose (a pentose sugar), a nitrogenous base and one phosphate group. You should distinguish between the normal and labelled nucleotides in the sequence for each … tRNA is involved in translation. 4. a year ago. It is essential therefore that cells contain a copy of this genetic code and that it can be passed on to new cells without being damaged. 47 times. The stop codon does not code for an amino acid and therefore the ribosome detaches and translation ends. Gene Mutations A mutation in a gene is a change in the base sequence of the DNA. Different sequences of bases code for different amino acids. There are four DNA bases, (GCTA), and therefore three bases are needed to make enough combinations to code for at least 20 amino acids. RNA is a polymer of a nucleotide formed of a ribose, a nitrogenous base and a phosphate group. Quality Assured. Each tRNA is specific to one amino acid, determined by the anticodon on it (three base). Biology A Level Revision Quiz. There are three types of RNA; mRNA, tRNA and rRNA. Some RNA is also combined with proteins to create ribosomes. OCR Biology A Module 2 Flashcards. ★ OCR A Level Biology (Biology A) Specification Reference: - 6.1.3 Manipulating genomes (e) the principles and uses of electrophoresis for separating nucleic acid fragments or proteins ★ OCR A Level Biology (Biology B) Specification Reference: - 5.1.3 Gene technologies (d) the principles and uses of agarose gel electrophoresis. OCR A level biology: delivery guides. This codes for the amino acid methionine. This is how the double helix structure is created, as two chains twist. The enzyme DNA helicase breaks the hydrogen bonds between the complementary bases of the two DNA polymers within the double helix. Biological diversity . 0.0 / 5. Number of phophates in ATP. OCR Biology – Spec at a glance. ATP cannot leave the cell, where as glucose can. These three components are joined in condensation reactions by covalent bonds. A Level Biology OCR Biology A H420 Biology A is split into six modules.  It’s the order of nucleotide bases in a gene that determines the order of amino acids in a particular protein. This continues to occur until the ribosome reaches the stop codon at the end of the mRNA molecule. Within the nucleus there are free floating DNA nucleotides. tyrosine is coded for by ATA and ATG. (b) state that ribonucleic acid (RNA) is a polynucleotide, usually single stranded, made up of nucleotides containing the bases adenine (A), uracil (U), cytosine (C) and guanine (G), (c) describe, with the aid of digrams, how hydrogen bonding between complementary base pairs (A to T, G to C) on two antiparallel DNA polynucleotides leads to the formation of a DNA molecule, and how the twisting of DNA produces its ‘double-helix’ shape. 1. Gene mutations randomly occur during DNA replication. Nucleotides and Nucleic Acids (a) state that deoxyribonucleic acid (DNA) is a polynucleotide, usually double stranded made up of nucleotides containing the bases adenine (A), thymine (T), cytosine (C) and guanine (G) Nucleic acids come in two forms: DNA (deoxyribonucleic acid) and RNA (ribonucleic acid). Quickly memorize the terms, phrases and much more. ATP, or Adenosine Tri Phosphate, is an immediate source of energy for biological processes.For metabolic reactions in … Introns are sections of DNA that do not code for amino acids and therefore polypeptide chains. Where a pyramidine appears on one side, a purine appears on the other. (d) outline, with the aid of diagrams, how DNA replicates semi-conservatively, with reference to the role of DNA polymerase, (e) state that a gene is a sequence of DNA nucleotides that codes for a polypeptide, A gene is a sequence of DNA nucleotides that codes for a polypeptide (protein). The inorganic phosphate released during the hydrolysis of ATP can be bonded onto completely different compounds to make them more reactive. The bonds between the inorganic phosphate groups is a high energy bond, as shown in the diagram above. Mutations A mutation is a change in the DNA and this could result in a non-functioning protein being created. Different proteins have a different number and order of amino acids. Glucose cannot do this, as it does not contain phosphate groups. Thymine and cytosine and both single ring structures and are therefore pyrimidines. The monomer that makes up DNA is called a nucleotide. Save. Nucleotides are joined together by a Condensation Reaction between the Phosphate Group of one and … Not all the DNA is unzipped in one go as this increases the chances of copying errors resulting in mutations. The five organic nitrogenous bases are grouped into purines and pyramidines. Biology. AQA A-Level Biology Nucleic Acids Quick Questions. Chat; Life and style; Entertainment; Debate and current affairs; Study help; University help and courses; Universities and HE colleges; Careers and jobs; Explore all the forums on Forums home page » Transfer RNA is found only in the cytoplasm. These booklets, from OCR, contains a range of suggested activities and contexts to enrich the teaching of A level biology topics. In mRNA, groups of three adjacent bases are called codons. The two amino acids that have been delivered by the tRNA molecule are then joined via a peptide bond which is catalysed by an enzyme. OCR (A) A-Level Biology Revision. It is small and soluble so easily transported around the cell. The polymer of these nucleotides is called a polynucleotide. The function of RNA is to copy and transfer the genetic code from DNA in the nucleus to the ribosomes. ... A piece of DNA was analysed and 15% of its nucleotides were adenine. Unit of work, including PowerPoint lesson plans and student notes to print, as well as exam questions and mark schemes for some lessons Follows the New OCR A Level Biology [A] Specification, could be adapted to other exam boards Lessons follow the Oxford A Level Biology for OCR Textbook Happy Revising! Cram.com makes it easy to get the grade you want! Module 1: Practical Skills in Biology. a year ago. The OCR A level Biology specification is demanding with a wide breadth of content, data analysis and mathematical skills forming major parts of the course. __Translation __– where the mRNA joins with a ribosome, and a corresponding tRNA molecules brings the specific amino acid the codon codes for. The nitrogenous bases in RNA are adenine, guanine, cytosine and uracil. These bases are classed as either purines or pyrimidines depending on whether the base is a single or double ring structure. Adenine and guanine are both double ring and are therefore purines. 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