DNA, and RNA Flashcards
Heredity information (DNA) is organized in the form of genes located in the chromosomes of each cell.
When two organisms reproduce, their offspring receive genetic instructions, called genes, from each parent.
Heredity
Is the passing of genetic information from one generation to the next greener action through REPRODUCTION.
The genes determine which traits-or characteristics-each offspring will have.
A human cell contain thousands of genes in its nucleus, and each gene carries a separate piece of coded information.
DNA
DNA has a double helix shape, which looks like a twisted ladder.
DNA (Deoxyribonucleic Acid)
Are found in eukaryotic cells, such as plants and animals. There also found in prokaryotic cells, such as bacteria
DNA is made up of two strands.
The strands are chemically bonded together and form a double helix shape
Parts of DNA
1.DNA is made of 3 chemical groups.
A)A sugar molecule called Deoxyribose
B)A phosphate group
C)4 (Nitrogen Bases):
1. Adenine (A). 3. Guanine (G)
2. Thymine (T). 4. Cytosine (C)
Steps in DNA replication:
There are four steps…
Double Stranded DNA Unwinds
DNA unwinds and looks like a straight ladder.
DNA Molecule Unzips
Enzymes will divide the 2 strands between the nitrogen bases.
Complementary Bonding Of New Strand
Free floating DNA nucleotides diffuse into the nucleus. Enzymes will attach the nucleotides to both templates.
Production Of Two New Strands
2 new DNA strands are produced.
RNA (Ribonucleic Acid)
Is made up of ONLY 1 strand of nucleotides.
RNA is also made of 3 chemical groups
A) A sugar molecule called Ribose
B) A phosphate group
C) 4 Nitrogen Bases:
1. Adenine (A) 3. Guanine (G)
2. URACIL (U). 4. Cytosine (C)
Uracil (U) replaces Thymine in the RNA molecule.
What is the only part of a subunit that can change and what is the significance for changing this part?
Nitrogen bases they make up our genes.
What is the shape of the DNA molecule?
A double helix
What is the name of the sugar in the DNA backbone?
Deoxyribonucleic Acid
What parts of the subunit form the sides of the ladder and what parts form the rungs?
Sugar, phosphate, and the bases
What is the significance of the specific sequence of DNA?
It makes up different genes.
Suppose you know that the sequence of bases on one DNA strand is AGTCTCAGAGTCTCAG. What is the sequence of bases on the opposite strand?
TCAGAGTCTCAGAGTC
Assume that a 100 base pair of DNA double helix contains 45 cystosines. How many adenines are there?
55 pairs of adenine.
In addition to a phosphate group, a DNA nucleotide could contain
Thymine and deoxyribose
In nucleotides the letters A, G, C, and T represent
Nitrogenous bases
A certain protein is found in a mitochondria, chloroplasts, and bacteria. This provides evidence that plants and bacteria
Have some similar DNA base sequences
A characteristic of a DNA molecule that is not characteristic of a protein molecule is that the DNA molecule
Can replicate itself
Genes involved in the production of abnormal red blood cells have an abnormal sequence of
Bases
A child has brown hair and brown eyes. His father has brown hair and blue eyes. His mother has red hair and brown eyes. The best explanation for the child having brown hair and brown eyes is that
The child received genetic information from each parent
Variation in the offspring of sexually reproducing organisms is the direct result of
Sorting and recombining of genes
Hereditary traits are transmitted from the generation to generation by means of
Specific sequences of bases in DNA in reproductive cells
Genetic Mutation
Any change in DNA sequence is called a mutation. Mutations can be caused by errors in replication, transcription, cell division, or external agents. An agent that causes a change in DNA is called a mutagen. Mutagens include radiation, chemicals, and high temperatures. Forms of radiation, such as x-rays, cosmic rays, ultraviolet light, and nuclear radiation, are dangerous mutagens because the energy they contain can damage or break apart DNA.
Substitution Mutations
occur when part of one DNA chromosome breaks off and is added to a different chromosome in DNA.
Deletion Mutations
occur when a part of the DNA chromosome is cut out or left out.
Insertion (Addition) Mutations
occur when a part (piece) of a DNA chromosome is added to the original DNA chromosome.
Inversion Mutations
occur when part of a DNA chromosome breaks off and reattaches backwards.
Protein Synthesis
Protein Synthesis is the process of making PROTEINS for the cell. Proteins are very important because they become structures inside the cell and they control cell functions. Proteins are made based on the sequence of nucleotides in the DNA molecule.
Protein Synthesis consists of Two Processes
1) Transcription
2) Translation
- For both processes, RNA is needed to help in the productions of proteins.
Three RNA molecules are involved
- mRNA- messenger RNA
- rRNA- ribosomal RNA
- tRNA- transfer RNA
mRNA
brings instructions from DNA to the cytoplasm.
rRNA
binds to the mRNA and uses the instructions to assemble the amino acids in the right order.
tRNA
delivers amino acids to the ribosome to be made into a protein.
Transcription
The process of transcription, RNA makes a copy of DNA strand and occurs inside the nucleus.
Steps of Transcription
- DNA unzips and free RNA nucleotides bind to DNA and make a RNA strand called mRNA. (It looks like a COPY of DNA).
- mRNA breaks off the DNA strand and leaves the nucleus and enters the cytoplasm. DNA goes back to its normal shape.
Translation
The process of changing the information in mRNA into an amino acid chain, making a protein molecule.
Steps of Translation
- mRNA has already entered the cytoplasm from the nucleus and goes to the RIBOSOMES.
- Ribosomal (rRNA) attaches itself to the mRNA strand. It binds to every CODON.
- Transfer (tRNA) molecules carry amino acids and approach the ribosome. It makes a copy of the mRNA strand called an anticodon. For every codon, there is an anticodon.
EXAMPLE: mRNA codon is G-C-C; the tRNA antic don is C-G-G.
Biotechnology
- Selective Breeding/ Artificial Selection
- Genetic Engineering/ Recombinant DNA technology.
- Cloning
- Gel Electrophoresis
Selective Breeding
Humans control the traits that are desired. Examples: Fruit, Vegetables, Dogs, Cats, Horses.
Problem: traits that are desired do not always appear.
Genetic Engineering
Scientists combine two organisms DNA together to het specific traits. (genes) Enzymes will cut and recombine both DNA strands. Remove human gene and insert the gene into the bacteria DNA. Bacteria will reproduce NEW copies of the HUMAN GENE.
Steps of Genetic Engineering
- Have two strands of Human DNA and Bacteria DNA.
- Cut out a specific gene from Human DNA with an enzyme. Cut bacteria DNA with the same enzyme.
- Recombine desired human gene with Bacteria.
- Remove human gene from bacteria after it has been copied.
Cloning
Making an exact copy of one organism.
A) Donor Egg- Remove DNA from egg.
B) Donor DNA- 46 chromosomes
Gel Electrophoresis
1) Cut DNA with enzymes.
2) Place cut DNA (Blue Dye) into the gel, inside wells.
3) Run an electric current on the gel.
4) The smallest DNA fragments (pieces) will go to the bottom of the gel and the larger more slower.
