semester 2
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Semester 2. Post Test Evaluation Review. Selectively Permeable. Plasma membrane Lets some molecule in and out of the cell Does not allow others in and out (waste). Concentration inside/outside cell. The solute concentration outside the cell is high - PowerPoint PPT PresentationTRANSCRIPT
Semester 2
Post Test EvaluationReview
Selectively Permeable
• Plasma membrane• Lets some molecule in and out of the cell• Does not allow others in and out (waste)
Concentration inside/outside cell
• The solute concentration outside the cell is high
• Thus water wants to move out to balance the environment.
WITH vs. AGAINST
• WITH (goes from high to low) – Passive Transport– No energy– Osmosis, Diffusion, Facilitated
Diffusion• Against (goes from low to high)– Active Transport– Energy is Required– Pumps, endocytosis, exocytosis
Facilitated diffusion vs. Active Transport
• Both use proteins
• Facilitated diffusion – move WITH the concentration gradient
• Active Transport – moves AGAINST the concentration gradient
Solutions
Changing an Isotonic solution• Lets say we add salt to an isotonic solution• It becomes a hypertonic solution– Meaning higher concentration outside the cell– Water will move out of cell – Cell will shrink/shrivel up
Exocytosis
• Exo – means exiting• Exocytosis move LARGE substances out of the
cell that cannot get through the plasma membrane
• Hormones are large
Photosynthesis
• Converts LIGHT energy to CHEMICAL energy
Converting ATP to ADP – releases energy
• During Cellular Respiration
• Step 1 is adding a phosphate (storing energy)
• Step 2 is subtracting a phosphate (releasing energy)
Metabolic Pathway
• A – Animals give off CO2 and H2O during Cellular Respiration
• B – Plants give of H2O, O, glucose during Photosynthesis
Energy
• The ability to do work!
Autotrophs vs. Heterotrophs
• Autotrophs – makes their own food– Plants
• Heterotrophs – obtain food from other sources.– Animal, worms, mushrooms (they look like plants
but they actually absorb nutrients from around them, they do not go through photosynthesis)
Glycolysis
• Anaerobic – does not need oxygen• Breaks down glucose into 3 pyruvate
molecules
Energy is produced
• Energy is being produced in Figure B
• ATP to ADP
2nd law of Thermodynamics
• During Photosynthesis HEAT is given off• This follows the 2nd law of thermodynamics
Metabolic Processes
• Anabolic– Photosynthesis
• Catabolic– Cellular Respiration (c)
Alternative Pathway
• CAM– Cactus
• C4 – Other plants
Alcohol Fermentation
• Takes place in yeast and some bacteria
Balanced Equations
Photosynthesis
What limits cell size?
• Ratio of Surface Area to Volume
Cancer Cells
• Unrestricted/Unlimited GROWTH
Binary Fission
• Two Identical Cells are produced
Healthy/Efficient Cells
• Are SMALLER• Because they do not have to transfer and
diffuse materials over a large area.• Communication is also easier
Spindle Fibers
• A is pointing to the spindle fibers• The cells is in Metaphase of Mitosis
Mitosis - Interphase
• Cell carries on metabolism and normal cell functions
• Cell DNA replicates
Goal of Mitosis
• A newly formed cell in Mitosis has equal number of chromosomes as the parent cell.
• Replace damaged cells
Cell Cycle
• Cell duplicates its DNA during (S) the synthesis phase of the Cell cycle
• Also called DNA synthesis
Homologous Chromosomes
• They line up on the equator of the cell during Metaphase 1
• Only seen in Meiosis 1 up until anaphase when they get pulled apart.
Allele
• Is a form of a gene– A is one allele– a is another allele• Together they make up Aa
– Brown is one allele– Blond is another allele• Together the Dominant would be seen (brown)
Mitosis vs. Meiosis
• What is formed?
– Mitosis – 2 identical body cells with
– Meiosis – 4 different gametes
Gregor Mendel
• He tested and hypothesized the offspring of pea plants inherited their traits.
Genotype
• AA – homozygous Dominant• aa – homozygous Recessive• Aa - Heterozygous
Simple punnett square
• In Squirles, brown fur is dominant to silver fur. If a (HO) brown is mated with a silver and 8 offspring are produced how many would be expected to be silver?
• (HO) brown – BB• Silver – bb• If you crossed them all would be Bb – Brown• So all 8 would be brown!
Haploid vs. Diploid
• Haploid – half the number of chromosomes– 1n– Gametes– Produced through Meiosis
• Diploid – normal number of chromosomes – 2n– Body Cells– Produced through Mitosis
Forming a Zygote
• A – Meiosis• B - Fertilizations
Application of Punnett Square
• In flower, purple(R) is dominant to white(r). A homozygous purple flower is crossed with a white flower. All of the flowers in the F1 generation were kept together as a group for several years. They were allowed to self-pollinate only within their own group. What is the expected phenotype of the F2 flowers?
• P: RR x rr• F1: Rr (so we cross Rr x Rr)• F2: 75% purple (RR, Rr, Rr) & 25% white (rr)
Crossing Over
• Happens during Prophase 1 of Meiosis
Application of punnett square
• What is the probability that you will get:– MMXX, MmXX, MmXx, MMXx – 56.25%– MMxx, Mmxx – 18.75%– mmXX, mmXx – 18.75%– mmxx – 6.25%
When does a cell become haploid during Meiosis?
• Anaphase 1• When homologous pairs of chromosomes are
separated and pulled to opposite sides of the cell.
Anaphase 1 vs. Anaphase 2• Anaphase 1 – homologous pairs are separated
• Anaphase 2 – sister chromatids are separated
Typical human chromosome numer
• Body cell – 46 chromosome• Gamete (egg or sperm cell) – 23 chromosomes
True – breeding Crosses
• A true-breeding tall pea plant is crossed with a true-breeding short pea plant, and all the offspring are tall. What is the most likely genotype of the offspring assuming a single-gene trait?
• True – breeding means homozygous• P: TT x tt• F1: Tt