GENES and the NUCLEUS

Transcription

1 ENES and the NULEUS () DN the nucleus contains the set of that determines: (a) what each cell will become (muscle cell, nerve cell, eye cell, etc) (b) how each cell will (through the production of ) (c) when it will and (d) when it will the instructions in the nucleus are contained in a molecule called DN DN = composed of many units called each nucleotide has three sub-units here are 4 different types of bases in DN = = = = It is the order of the bases that forms the which is used by the cell to produce materials ( ) required by the cell DN is composed of long strands of nucleotides that are attached together by the down the middle. he DN molecule looks a lot like a, where the sugar and phosphate groups make up the and the bases make up the. Base Pairing Rule:

2 omplete the following DN molecule diagrams by adding the missing part. Be sure to add in bases following the base pairing rule ( and ) 1. a. b. c. d. e. f. g. h. ircle ONE nucleotide on the diagram to the left (B) HE NULEUS and ENES DN usually exists inside the nucleus as an uncoiled strand or strings called which are held together by proteins. when the cell is ready to, the strings of chromatin coil up into X-shaped structures called every species of organism has a characteristic of chromosomes fruit flies have 8 chromosomes (4 pairs), cows have 60 chromosomes (30 pairs), and humans have 46 chromosomes (23 pairs) each set of chromosomes carries different instructions (or genes) for the cell the 23 rd pair determines the sex/gender of the organism (XX = female, XY = male)

3 are found on chromosomes genes are small segments of DN genes store the information needed to make thousands of different used in the cells of the body. genes are located in specific location on chromosomes ex) ene for Freckles located on chromosome #4 humans have pairs of chromosomes HE BI PIURE 22 pairs appear 1 pair has sizes (X and Y) all cells contain chromosomes in called homologous pairs (homologous means they look similar) you received 23 chromosomes from your and 23 chromosomes from your ENE = of DN containing information each chromosome carries a of the gene which is called an usually, one allele is dominant over another allele. his means if you have both alleles, you will only show the dominant trait. Example: Freckles wo alleles: (a) (dominant) (b) (recessive) enetic ode (enotype) FF Ff ff Physical rait (Phenotype) () WH RE PROEINS? long strings/chains of acids used by cells to a variety of proteins have many important functions in the body, for example: (a) cells in digestive system produced proteins called enzymes which help break down food (b) cells in glands can produce hormones such as insulin which is needed to maintain normal sugar levels in your blood (c) cells can produce protein pigments used to colour your hair, skin, and eyes. produced in the cell by the DN code into an amino acid

4 ENEI ODE Phenylalnine (Phe) Leucine (Leu) Leucine (Leu) Isoleucine (Ile) Methionine (start) (Met) Valine (Val) Serine (Ser) Proline (Pro) hreonine (hr) lanine (la) yrosine (yr) Stop Stop Histidine (His) lutamine (ln) sparagine (sn) Lysine (Lys) spartic acid (sp) lutamic acid (lu) ysteine (ys) Stop ryptophan (rp) rginine (rg) Serine (Ser) rginine (rg) lycine (ly) codes of DN are used to produce the chain which makes up the ex) DN Sequence : mino cid Sequence : RY RNSLIN HESE!! 1) DN Sequence : mino cid Sequence : 2) DN Sequence : mino cid Sequence : What do all these sequences have in common?

5 (D) MUIONS MUION = or to the (genetic material) of a living organism Example: Substitution one base (letter) is substituted for another Normal DN: Mutated DN: Protein Example: Deletion/ddition one base is left out or added Normal DN: Mutated DN: anything that causes a mutation is called a ex) mutations can cause a variety of different effects: (1) POSIIVE MUIONS a in DN that causes the production of a protein, which the organism ex) (2) NEIVE MUIONS a in DN that causes the production of a protein, which the organism ex) DN a.a. Valine Histidine Leucine hreonine Proline lut. cid lutamate Here is the same section after one base (a in the 6 th codon) has been substituted with an. DN a.a. Valine Histidine Leucine hreonine Proline Valine lutamate (3) NEURL MUIONS SIKLE ELL NEMI Mutation causes red blood cells to change from their normal roundshape to a sickle shape. he sickle cells block the veins and arteries. s fewer and fewer normal red blood cells are able to pass through the congested blood vessels, the tissue and cells become starved for oxygen and other nutrients. a change in DN that does change the that is produced. Normal DN: Mutated DN:

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