DNA: The Genetic Material (Gen Zoo Quiz 4) PDF

M2 - L3. DNA: The Genetic Material it’s all in the dna! the secret of our great looks is through the dna DEOXYRIBONUCLEIC ACID a biological macromolecule with structural unit dna’s general structure : nucleotide (the monosaccharide part of it) ○ 1 nucleotide is composed of...

M2 - L3. DNA: The Genetic Material it’s all in the dna! the secret of our great looks is through the dna DEOXYRIBONUCLEIC ACID a biological macromolecule with structural unit dna’s general structure : nucleotide (the monosaccharide part of it) ○ 1 nucleotide is composed of a phosphate group, a pentose sugar (5 carbon sugar), and nitrogenous bases in the dna, the most important thing are the nitrogenous bases, they are the ones we need to base pair the DNA has two twisted strands, called double helix, and described like a twisted ladder. The sides of the ladder is made up of alternating molecules of phosphate and sugar (deoxyribose) in which covalent bonds join the sugar of one nucleotide to the phosphate group of the next nucleotide, forming the sugar-phosphate backbone. Whereas, the rungs are composed of the nitrogenous bases, the adenine and guanine of the purine group, and the cytosine and thymine of the pyrimidine group. pyrimidine & purines Purines  much larger kasi may two rings ○ puga - guanine & adenine Pyrimidines only have a single ring ○ pycut- cytosine, uracil, thymine base pair : a&tg&c RIBONUCLEIC ACID still made up of the phosphate group (backbone), nucleotide (nitrogenous bases), ribose sugar always a single stranded molecule but always may base pair ○ a&u ○ g&c nawala si thymine, na-replace ng uracil Frederick Griffith Experiment (1928) Genetic Transformation ○ Working on a bacteria known “Streptococcus pneumoniae” Has two types of strain Smooth strain (virulent or poisonous) ○ Cells of smooth strain have a protective layer known as the capsule, which protects the cells against the immune system Makes the smooth strain highly pathogenic Rough strain (nonvirulent) ○ Lacks a capsule so the immune system can easily kill it  ○ When the cells of the rough strain are injected into a mouse, the mouse lives ○ When the cells of the smooth strain are injected into a mouse, the mouse dies ○ But when the cells of the smooth strain are killed by heat and injected to the mouse, the mouse lives ○ But when the heat-killed smooth strain is mixed together with the rough strain and injected into the mouse, the mouse dies This is because it feels like there is something on the smooth strain that is being transferred to the rough stain that makes it also a smooth strain and makes the mouse die They said it was the DNA James Watson and Francis Crick they did not discover dna or even if dna contained genetic info nauna lang sila mag-publish Along with Maurice Wilkins, 1962 Rosalind Franklin first to confirm the helical structure of dna ○ Photo 51: DNA fibre (with Raymond Gosling, 1952) not recognized for her work, naunahan nila watson died at the age of of 37 due to ovarian cancer x-ray diffraction central dogma of life refers to the processes involved on how the genetic information of the DNA is converted into gene products, RNAs and proteins. 1. replication (dna —> dna) done by the dna polymerase chain replicate and make a conservative copy of the dna 2. transcription (dna —> rna) transcribing dna to go into the rna molecule with the help of rna polymerase magppair na as rna, lalabas na sa nucleus, pupunta na to the cytoplasm 3. translation (rna —> protein) from rna to a specific protein why proteins? proteins is one of the most important out of all the biomolecules because it constitutes all or almost all of our body. dna replication key players Helicase unzipping enzyme dna polymerase building enzyme primase initiating enzyme ligase glue-ing enzyme pag may ase, it’s an enzyme replication 1. DNA Replication, by which DNA makes new DNA. This is a biological process in which DNA makes a copy of itself. It has four(4) steps, these are fork formation, primer binding, elongation and termination. Fork formation is the split of the two(2) strands of DNA, in which each of the single strands becomes the template of the new strand of a complementary DNA. This is the pairing of the bases in the template strand, the adenine paired with thymine, and guanine with cytosine. Primer Binding is the binding of primers to DNA template by complementary base pairing to start the replication. A primer refers to the nucleotides of DNA, with 18 to 24 base pairs in length. Elongation is the lengthening of the DNA by the addition of nucleotides to the 3’ end of the newly synthesized strand. The DNA nucleotides added are specified by the template strand, as to whether A, T, C, or G. The Termination Phase is the end of DNA synthesis. This happens when the two replication forks meet, DNA is unwound, and gaps are filled. how dna replicates : The dna is always in a double helix, so pano natin siya matatanggal ? the helicase unwinds the dna, the helicase is just like a zipper, it would open up the dna, ibubukas niya yan. pag dumating si helicase, it would open. once the helicase have unzipped the double helix formation, your dna polymerase will now work. habang nagbubukas yan, meron na agad gumagawa, which is si dna polymerase. malungkot yung polymerase sa baba kasi dna polymerase only works from 5 to 3 prime. pag leading strand (5-3), pag lagging strand (3-5). once you have the signals (flag) sa unahan, the dna polymerase will now build a base partner; making an exact copy of the strand. pero yung lagging strand naman, yung nahuhuli, ay nahihirapan mag-build bc the dna polymerase could not react from 3 to 5 prime. once this is building sa 5-3 prime, darating si primase. primase would send out signals if there are gaps in between of the fragments. pag nagssignal na si primase, may darating na. pag si primase nag-put na ng signal, meaning may putol dito and need natin ibuild. those fragments are called okazaki fragments. di pwede sa dna na may putol or deletion, so dapat may magbbuild in between. para mabond yung okazaki fragment, si ligase magwwork. para walang gap in between. that is why at the end, we have a semi-conservative replicated copy of the dna. almost the same. 99% pareho. they both have the og strands and the new strands after the dna is replicated in the nucleus, it would be transcribed in the cytoplasm transcription when DNA makes new RNA. In this process, DNA segment is copied into RNA molecules, the messenger RNA (mRNA). The mRNA leaves the nucleus and goes out to the cytoplasm to direct protein synthesis. This time, thymine is replaced by uracil. synthesis of an rna strand (messenger RNA /mRNA) from a dna template 3 types of rna : ○ messenger (mRNA) provides the template for protein synthesis during transcription ○ transfer (tRNA) brings amino acids and reads the genetic code during translation ○ ribosomal rna (rRNA) plays for structural and catalytic role during translation marami pang more types ng rna na pwede ma-encounter sa transcription and translation, pero eto yung mga basic codon - sequence of 3 dna or rna nucleotides that corresponds with a specific amino acid !!! dapat laging 3 in the sequence to make 1 amino acid aug (methionine) start codon magsstart ng translation uag, uaa, uga stop codon magsstop ng translation for example we have the codon : cca aug ggc aaa gca uaa ○ magsstart sa aug, kasi yun yung start codon ○ di magkakaroon ng protein synthesis hanggang walang aug, kahit marami pa man nauna diyan, walang mangyayari ○ walang kwenta yung nauna, pangpalito lang ○ sa uaa, hihinto na. yan na yung end. basta pag nakita na stop codons, magsstop na translation. ○ may 5 proteins na magagawa (starting from aug - uaa) translation in which proteins are made from RNA. This is a process when mRNA acts as a template in the synthesis of protein. synthesis of proteins directed by mRNA template mRNA —> tRNA  start looking inside, going out M2 - L4: Inheritance Patterns of Animals The characteristics of organisms are influenced by genes, which are pieces of DNA that are in the chromosomes. These genes are responsible in carrying the characteristics of organisms from the parents to their offspring. This is stated in the Laws of Inheritance. There are 3 Mendelian Laws of Inheritance, these are: (1) Law of Segregation, (2) Law of Independent Assortment, and (3) Law of Dominance. Whereas, the 3 Non-Mendelian Laws of Inheritance are: (1) Law of Incomplete Dominance, (2) Law of Co-dominance, and (3) Multiple Alleles. 3 Mendelian Laws of Inheritance: Law of Segregation ○ Says that everyone has two versions ( called alleles) for each trait, that randomly segregate during meiosis. This means that in fertilization, when an egg is joined by a sperm, one new organism is produced, with genotype consisting of the alleles contained in the gametes. Law of Independent Assortment ○ This says that the alleles of two or more different genes are categorized into gametes independently of one another. This means that the allele of a gamete for one gene does not influence the allele of another gene. ○ This law was introduced by Gregor Mendel after doing dihybrid crosses. Where he noticed that new combinations of traits emerged from the cross of two parents with different combinations of two traits.  Law of Dominance ○ Dominant alleles always hide recessive alleles. ○ It states that each individual has two copies of gene, these are the dominant traits and the recessive traits. Where dominant traits are inherited characteristics that are phenotypically expressed in heterozygous organisms, while recessive traits are present at the gene level, but are masked and unexpressed. 3 Non-Mendelian Laws of Inheritance Law of Incomplete Dominance ○ This occurs when the dominant allele does not completely mask the recessive allele, so an intermediate phenotype is observed and this results to the blending of the two alleles. Law of Co-Dominance ○ The genetic traits of different alleles of the same gene-locus are both expressed phenotypically. This means that both alleles are seen in the phenotype at the same time. Law of Multiple Alleles ○ This means that genes exist in several different forms. An individual has only two copies of each gene, but many different alleles are within a population.