Biology Past Paper PDF - Chapter 1

Strand: Life at molecular, cellular and tissue level DNA: The Code of Life CHAPTER 1: DNA – THE CODE OF LIFE DNA and RNA All living organisms contain both DNA (deoxyribonucleic acid) and RNA (ribonucleic acid). Focus: Location, structure, and function of DNA and RNA. Protein...

Strand: Life at molecular, cellular and tissue level DNA: The Code of Life CHAPTER 1: DNA – THE CODE OF LIFE DNA and RNA All living organisms contain both DNA (deoxyribonucleic acid) and RNA (ribonucleic acid). Focus: Location, structure, and function of DNA and RNA. Protein Synthesis Protein synthesis is vital for life. Examine how proteins are formed by both DNA and RNA. REVISION OF CELLUAR STRUCTURE Cytoplasm Is the base substance in which the organelles of cells are suspended. It is a watery substance and allows for metabolic reaction to take place. Ribosomes Small, round organelles which are mainly found attached to the endoplasmic reticulum or are free floating in the cytoplasm. Ribosomes can also be found inside other organelles such as the chloroplast and mitochondria but in smaller numbers. They are the site of protein synthesis and consist of RNA and protein. A NUCLEUS HAS 4 MAIN PARTS: Double nuclear membrane It encloses the nucleus and contains small pores to allow for the passage of substances in and out of the nucleus Nucleoplasm Jelly-like Fluid within the nucleus Nucleolus A dark body suspended in the nucleoplasm which contains free nucleotide bases and produces Ribosomes Chromatin network Found in the nucleoplasm – contains the DNA which forms the chromosomes containing the genetic code of a person/ organism THE STRUCTURE OF NUCLEIC ACIDS KEY TERMS Nucleic Acid A type of organic compound Monomer A building block Nucleotide The monomer which DNA and RNA THE Human Body has 2 nucleic Acids in the human body 1. DNA ((deoxyribonucleic acid) 2. RNA ((ribonucleic acid) Together these form the basis of all life on Earth - They Consist of Monomers (building blocks) called nucleotides. DNA – deoxyribonucleic acid DNA Deoxyribonucleic acid is made up of nucleotides Nitrogenous bases ADENINE, THYMINE, GUANINE AND CYTOSINE Carries the genetic code for protein synthesis Nuclear DNA DNA found in the nucleus Extra- nuclear DNA DNA found outside the nucleus: Mitochondrial and chloroplast DNA