Lab Practical 1 Flashcards
• Catalysts
substance that speeds up a reaction without being changed in the process.
Two types of microscopes
The dissecting and compound microscope.
• Enzyme
a protein that serves as a biological catalyst, changing the rate of a chemical reaction without itself being changed into a different molecule in the process
• Substrate
- a substance that an enzyme acts on
substrate from lab
hydrogen peroxide
enzyme from lab
catalase
end products from lab
water & oxygen
blended up liver is called the
homogenate
enzymes are highly ____________.
specific
as the concentration of enzyme increases….
the rate of enzyme reaction increases
enzymes work best at the temperature ________.
they are designed for
we used ______ to make our concentration more acidic and _____ to make our solutions basic.
hydrochloric acid & sodium hydroxide
Two basic functions of a microscope.
Magnification and resolving power
Magnification
the increase in the apparent size of an object
Resolving power
a measure of the clarity of an image; it is the ability of an optical instrument to show two objects as separate
Three features of a dissecting microscope.
You would use a dissecting microscope rather than a compound microscope to view opaque objects or objects that light cannot pass through Dissecting microscopes have much lower total magnification than compound microscopes Dissecting microscopes do not invert the image of the item under view
enzymes work best at what pH?
The one they are designed for… 7
What are the four molecules of life?
Lipids, carbohydrates, proteins, nucleic acids
Organic molecule
• Organic molecule - carbon containing compounds produced by living organisms
The organic molecules in our food are used to
o provide energy to our cells o provide the molecules of life (building blocks) to make new cells and cell products
Fatty acids are the ______.
Monomer. (Smallest part)
Types of lipids
triglycerides (fats & oils), phospholipids (major component of cell membranes) steroids (including cholesterol & steroid hormones)
Define hydrophobic and hydrophilic. Lipids are…
• Lipids are hydrophobic - they do not mix with water o Hydrophilic – molecules that mix with water
Triglycerides can be broken into 2 categories
Unsaturated (from plants) liquid Saturated (from animals) solid
Which molecule has the most calories per gram?
Lipids
Saturation
o saturation – based on the number of hydrogen atoms attached to each carbon in the molecule
hydrogenation
o hydrogenation - the process of increasing the number of hydrogen atoms attached to carbon atoms (increasing the saturation) in an unsaturated fat • used to make solid margarine from liquid plant-based oil
Emulsifier
Emulsifier - chemical used to help mix lipids and water o an emulsifier has both hydrophobic and hydrophilic properties o common example: dish soap
Carbohydrates
• These molecules are the most common fuel (energy) molecule for living cells
Benedict’s reagent
• Benedict’s reagent - chemical that reacts and changes color in the presence of most monosaccharides and disaccharides (excluding sucrose) but does not react in the presence of polysaccharides o Negative test = stays sky blue o Positive test = changes to green, yellow, red to brown
Iodine
• Iodine (Lugol’s solution)- a chemical that reacts and changes color in the presence of starch (a common polysacharide) o Negative test = light yellow or yellowish brown o Positive test = dark blue-black or very dark purple
Proteins
• Proteins serve as enzymes, some hormones, and structural components of tissues
Features of a compound microscope.
Be able to explain & visualize that compound microscopes invert the image of a specimen. (e.g. what does the letter “f” look like under the compound scope?) The relationship between “depth of field” and magnification is an inverse relationship (as one increases the other decreases) Know the basic procedures of using the microscope (e.g. only use coarse focus with scanning objective lens; put microscopes away with scanning lens in place & stage lowered; only use lens paper to clean the lenses; etc.)
- Plants and animal cells are examples of what type of cells (unlike bacterial cells)
- Eukaryotes
- Name two structures that plant cells have that animal cells do not
- Cell walls, central vacuoles, chloroplasts
- Name the two main types of cells in the blood.
- Leukocytes (white blood cells) and erythrocytes (red blood cells)
- Where does the substrate bind on the enzyme?
- The active site
- The respiration process performed by yeast and involved in rising of bread is called ____________
- Fermentation
- A denatured enzyme loses its shape and thus, loses its __________
- Ability to function
- What function of the microscope is defined as the increase in the apparent size of an object?
- Magnification
- As the magnification increases, the depth of field (the distance between the nearest and farthest parts of the specimen that are in focus):
- Decreases
- Which microscope inverts the image in the field of view?
- Compound microscope
- What is the term for a chemical that helps mix lipids and water?
- Emulsifier
- To make a positive control test for the presence of sugar, would you add H20 or 5% glucose to your Benedicts reagent?
- 5% glucose
- Which molecule of life is typically hydrophobic?
- Lipids
- Name one type of symbiotic relationship
- Parasitism or mutualism (there is also commensalism, but we did not cover that)
- A plant that lives and reproduces for many years is called a _______________
- Perennial
- The honeysuckle plant or the Bradford pear tree, introduced into its non-native habitat and growing out of control is an example of what type of species?
- Invasive
- Once your data is plotted, what must be determined before you can determine whether to accept or reject a hypothesis?
- Whether your data sets are different
- If the data from two groups plotted on a number line overlap, what can we conclude about the experimental groups?
- They are not different
- What is the purpose of the negative control group?
- Something to compare the experimental group to, a baseline, a way to see what a negative result will look like.
o Annual
– a plant that lives and reproduces during a 1 year time span
o Biennial
– a plant that lives and reproduces during a 2 year time span, often reproducing the second year
• Levels of ecological organization
o Population – members of one species in a given area o Community – all of the living things in a given area o Ecosystem – both the living and nonliving elements of a particular area that interact and affect the life in that area
Nonpoint pollution
pollution that enters the environment from widespread origins, especially as the result of runoff after rain
Levels of energy transfer in the living world
o Producers (autotrophs) – o Primary consumers – o Secondary consumers – o Decomposers –
ecology
he study of the interactions between organisms and between organisms and their nonliving environment
Cell theory
o All living things are composed of cells and the products of cells
o All cells come from previously existing cells
o Cells are the fundamental units of life
• Tissues – groups of cells of the same type involved
The building blocks of proteins are
Amino acids
