Lab Practical Flashcards
What are the 5 steps of the scientific method?
- Observation
- Questions
- Hypothesis
- Predictions
- Testing
Hypothesis
A statement that provides a possible explanation for an observation
Prediction
A prediction is a guess what might happen based on observation.
Independent Variable
is the variable that is changed or controlled in a scientific experiment (x-axis)
Dependent Variable
It is the variable being tested and measured in a scientific experiment. (y-axis)
What are the two basic types of microscopes?
Light and electron(electromagnentic) microscopes
Magnification of a microscope
It makes objects larger
Resolution of a microscope
Is the ability to distinguish fine detail
The contrast of a microscope
It helps make an image easier to see because the contrast is the difference between light and dark areas
Resolving Power
Is the ability to distinguish two adjacent points as distinct and separate
Light Microscopes
Light microscopes use glass lenses and light. The highest resolution is 0.2 micrometers
Electron Microscopes
They use an electron beam focused by magnets to illuminate a specimen.
Diffusion
is the process of random movement toward a state of equilibrium
What does diffusion do?
- They have molecules from an area of higher concentration to one of lower concentration
- can occur in any medium (liquid, solid, gas)
- Doesn’t require a semipermeable membrane
Osmosis
The net movement of a solvent across a selective permeable membrane into a region of higher solute concentration
What does osmosis do?
- Can only occur in liquid
- requires a semipermeable membrane
- movement seeks to equalize solvent concentration (although it doesn’t achieve it)
What are the 3 terms used to compare solute concentrations of 2 solutions separated by a membrane?
- Hypertonic
- Isotonic
- Hypotonic
Hypertonic
The solution has a higher solute concentration than the other solution
Isotonic
The solution has an equal solute concentration
Hypotonic
The solution has lower solute concentration than other solution
What is a selective permeable barrier?
It blocks some substances while permits other substances to enter a cell
What is the basic structure of a prokaryotic cell?
- It has a cell membrane
- Lacks membrane-bound organelles
- Have nucleoid, where their chromosomes are organized
- have circular chromosomes
- Have ribosome
What do all cells have?
They all have a plasma membrane, a cytoskeleton, and ribosomes
What do all eukaryotic cell have?
- They have a nucleus
- They have a linear chromosome
- They are 10-100 times bigger than prokaryotic cells
- They contain membrane bound organelles that perform a certain function
Catalysts
Are substances that speed up reactions without being permanently altered
Enzymes
Are biological catalysts that are mostly protein, except RNA molecules, called ribozymes
Substrate
Are reactants that bind to a specific site on the enzyme
Active Site
A specific site on the enzyme where the reaction occurs
Enzyme-substrate complex (ES)
The binding of a substrate to the active site of an enzyme that are held together by H-bonding, electrical attraction, or temporary covalent bond
Substrate concentration affects what?
It affects the rate of an enzyme-catalyzed reaction
What affects enzymes speed?
- Warming increases rates of chemical reactions, but if the temperature is too high, non-covalent bonds can break and inactivate enzymes
- pH levels
Photosynthesis
Is the process of capturing energy from sunlight
Light-dependent reactions
Are enzymes that only work in light and convert light energy into chemical energy (in ATP and the reduced electron carrier NADPH)
Light-independent reactions
It uses the ATP and NADPH from the light-dependent reaction along with CO2 to produce carbohydrates
Light
Is a form of electromagnetic radiation, which travels as a wave but also behaves as particles
How many ATP can be made in the Calvin cycle?
54 ATP
Cellular Respiration
Is the set of metabaolic reactions used by cells to harvest energy from food. It is a catabolic pathway and glucose is oxidized
What is the general equation for photosynthesis?
6CO2 + 6H2O + light energy = 6O2 + carbohydrate
Aerobic Metabolism
A set of chemical reactions that releases energy from life’s molecule by using O2
Anaerobic Metabolism
A set of chemical reactions that extract energy without O2
How many ATPs are made during one aerobic respiration?
32 ATPs
How many ATPs are created during fermentation?
2 ATPs
Anaerobic Fermentation
is the process of energy production in the absence of oxygen.
What is Paper chromatography?
It is a method that is used to separate the different pigments involved in photosynthesis
What are the two groups of pigments in photosynthetic organisms?
- Chlorophyll A and B pigment
2. Carotenoid pigment
Carotenoid Pigments
Are accessory pigments that absorbs wavelengths of light between the red and blue wavelengths, and transfer a portion of that energy to the chlorophylls
Chlorophyll A
Is the primary pigment of photosynthesis and absorbs orange-red and blue-violet light
Chlorophyll B
Is the accessory pigment of photosynthesis and is not necessary for photosynthesis to occur and absorbs blue light
Mitosis
ne nucleus produces two daughter nuclei, each containing the same number of chromosomes as the parent nucleus and the products are identical to each other
Gene Flow
Migration or mating of individuals between populations that introduces variation
Genetic Drift
is a mechanism of evolution in which allele frequencies of a population change over generations due to chance (sampling error). It is faster in smaller population
Founder effect
Occurs when new individuals that find a new place to live and colonize (special bottleneck)
Population Bottlenecks
occur when a random disaster occurs and a few individuals survives (passes through a narrow neck of a bottle)
Allele Frequencies
refers to how common an allele is in a population. It is determined by counting how many times the allele appears in the population then dividing by the total number of copies of the gene.
Genotype Frequencies
shows how a population’s genetic variation is distributed among its members
shows how a population’s genetic variation is distributed among its members
Acts to reduce variation without changing the mean value of a trait (birth weight)
Directional selection
Acts to shift the mean value of a trait toward one extreme ( Texas Longhorn cattle)
Disruptive selection
favors both extremes of trait values, resulting in a bimodal character distribution ( bill size in the black-bellied seedcracker of West Africa.)
The genotype of an organism
Is the listing of the two alleles for each trait that it possesses
The phenotype of an organism
Is a description of the way a trait is displayed in structure, behavior, or physiology of the organism