genetic transformation and protein synthesis. basic unit of life cells made of –outside (cell...
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Genetic Transformationand
Protein Synthesis
Basic Unit of Life• Cells• Made of
– outside (cell membrane)– Inside (cytoplasm and organelles)
• Governed by genetic material (DNA)– DNA wrapped in a membrane = nucleus
• Characteristic of EUKARYOTIC cells (plants, animals, fungi, protists, etc)
– DNA loose in cytoplasm = nucleoid region• Characteristic of PROKARYOTIC CELLS (Bacteria)
DNA Extraction
• Virtual lab
• http://learn.genetics.utah.edu/content/labs/extraction/
Are their cells different sizes?
Cell Size
• Cells cannot grow to unlimited size
• Nucleus cannot control movement into and out of cell membrane
• Not enough of assorted organelles to get necessary work done (proteins made, waste removed, etc.)
• Key is surface area to volume ratio– A cell must have enough membrane on the
outside (ie, surface area) to control what enters and leaves the cell.
Fill in the data chart
S = width of one side
S2 = surface area of one sideX 6 = total surface area
S3 = volume
Surface area to volume ratio
Cells divide so they can maintain homeostasis.
• Requires copies of all cell contents including DNA
• DNA copies by semi-conservative replication.– Each strand is half old and half new.
• MITOSIS: Basic cell division for growth and repair.– Interphase (G1, S and G2)
– M phase:
Prophase, Metaphase, Anaphase,
and Telophase …
– followed by Cytokinesis
– Results in two “daughter” cells
Phases of the cell cycle:Phases of the cell cycle:
Plants use cell plate to separate new cells until cell wall can be made.
DNA Structure: The Double Helix
Basic unit is a nucleotide made of:
• Sugar (deoxyribose)
• Phosphate
• Nitrogenous base
• purines (double ring)
• pyrimidines (single ring)
Photo 51
DNA Replication occurs in “S” portion of Interphase.
• DNA must be copied so every new cell has the same number and same kind of chromosomes as every other cell.
• Process is
semi-conservative
Principle of Base Pairing
Adenine-Thymine
Held together by two hydrogen bonds
Cytosine-Guanine
Held together by three hydrogen bonds.
Sister chromatids
Shorter arm
Longer arm
THE STRUCTURE OF DUPLICATED CHROMOSOMES THE STRUCTURE OF DUPLICATED CHROMOSOMES AS SEEN IN METAPHASEAS SEEN IN METAPHASE
Human karyotype: n=23, 2n=46Human karyotype: n=23, 2n=46
Mutations
How is RNA different from DNA?
• Ribosomal RNA (rRNA)
• Transfer RNA (tRNA)
• Messenger RNA (mRNA)
Types of RNA
Types of RNA• Messenger RNA (mRNA) – consists of RNA nucleotides in the
form of a single uncoiled chain. – mRNA carries genetic information from the nucleus to the
cytosol. • Transfer RNA (tRNA) - consists of a single chain of about
80 RNA nucleotides folded into a hairpin shape that binds to specific amino acids. – tRNA carries amino acids from the cytoplasm to the
ribosomes. – About 45 varieties of tRNA.
• Ribosomal RNA (rRNA) - most abundant form of RNA. – rRNA consists of RNA nucleotides in a globular cluster. – Joined by proteins, rRNA makes up the ribosomes where
proteins are made.
Protein Synthesis