Biology Flashcards 3.0 / 5 based on 1 rating ? ScienceBiologyGCSEOCR Created by: Sarah BurdettCreated on: 03-01-13 16:11 What do animal cells have that plant cells do not? Ribosome and Mitochondria 1 of 22 What happens in a ribosome Protein Synthesis 2 of 22 What happens in mitochondria? Respiration providing energy for cell processes 3 of 22 What are chromosomes? Long molecules of coiled up DNA. The DNA is divide into short sections called genes. 4 of 22 Describe the appearance of DNA DNA is a double helix (a double-stranded spiral). Each of the two DNA strands are made up of lots of small groups called 'nucleotides' 5 of 22 What are the four bases? Each nucleotide has contains a small molecule called a 'base'. DNA has four bases : A,C,G and T 6 of 22 What do the bases do? Each base forms cross links to a base on the other strand. This keeps the to DNA strands tightly sound together 7 of 22 What base pairs with what base? A always pairs with T and C with G, this is complementary base-pairing 8 of 22 Who discovered DNA? Francis Crick and James Watson were the first scientists to build a model if DNA (1953) 9 of 22 How did they discover DNA? They used data from other scientists to understand the structure of a molecule. This included: X-ray data 10 of 22 How does DNA replicate itself (1)? 1) DNA copies itself every time a cell divides, so that each new cell still has the full amount of DNA 11 of 22 How does DNA replicate itself (2)? 2) In order to copy itself, the DNA double helix first 'unzips' - to for, two single strands. 12 of 22 How does DNA replicate itself (3)? 3) New nucleotides then join on using complementary base-pairing. This makes an exact copy of the DNA on another strand. 13 of 22 How does DNA replicate itself (4)? 4) The result is two double-stranded molecules of DNA that are identical to the original molecule of DNA. 14 of 22 How are proteins made (1)? DNA contains the production of proteins (protein synthesis) in a cell. 15 of 22 How are proteins made (2)? A section of DNA that codes for a particular proteins called a gene 16 of 22 How are proteins made (3)? Proteins are made up of chains of molecules called amino acids. Each different protein has it's own particular number and order of amino acids. 17 of 22 How are proteins made (4)? This gives each protein a different shape, which means each protein can have a different function. 18 of 22 How are proteins made (5)? It's the order of the bases in a gene that decides the order of amino acids in a protein. 19 of 22 How are proteins made (6)? Each amino acid is coded for by a sequence of three bases in the gene. 20 of 22 How are proteins made (7)? The amino acids are joined together to make proteins, following the order of the bases in the gene 21 of 22 How are proteins made (8)? Each gene contains a different sequence of bases - which is what allows it to code for a unique protein. 22 of 22
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