Midterm Review Flashcards
Phosphorus is an important element in building which macromolecules?
Nucleic acids and (Phospho)lipids
What is an independent variable?
The manipulated variable
What is a dependent variable?
The measured variable.
What is used to ensure that no confounding/outside variable has affected the results or to factor in any likely sources of bias?
A control
What is the most accurate reason for why null hypotheses are used?
It enables the hypothesis to be tested using statistical analysis
What does a low standard deviation mean?
The independent variable is likely causing the changes in the experiment.
What does a carboxyl group look like?
COOH
What is responsible for the adhesive properties of water?
Hydrogen bonds between water and other molecules
Which macromolecule do plants use for storage?
Carbohydrates
Know the phenomenon on number 9. of the review.
“When NaCl is exposed to water the positive charges of the water are attracted to the negative Cl and the negative charge of the water molecules are attracted to the positive Na.”
What causes ice to float?
Hydrogen bonds; they stabilize the structure of water, keeping water molecules apart causing ice to be less dense.
According to the endosymbiotic theory, mitochondria and chloroplasts are believed to have evolved through a symbiotic relationship originating when an early ancestor of eukaryotic cells engulfed a prokaryotic cell. What is the evidence to support this theory?
Mitochondria and chloroplast have their own DNA, can self replicate, and can perform transcription and translation
You are examining a cell that has a high rate of protein synthesis. Knowing this, what cellular component would you expect to see large numbers of?
Ribosomes
What is the function of the Mitochondria?
Cellular respiration
What is the function of chloroplasts?
Photosynthesis
What is the function of lysosomes?
Clean up old parts
What is the function of the vacuole?
Storage
At the gym an athlete decided to push himself to bench press more than what he was ready for. Due to the overly heavy weight, he damaged his pectoral (chest) muscles and had soreness for one week. Which part of the cytoskeleton was most likely damaged in the pectoral muscle cells?
Microfilaments
If analyzing the membrane composition of an organism living in a cold climate, what would you expect to find?
Many unsaturated fatty acid chains to prevent tight packing of the phospholipids.
To be most efficient at exchanging material across the plasma membrane, a cell must have what kind of SA:V ratio?
Low
To be best for storage of materials, a cell must have what kind of SA:V ratio?
High
Intestinal cells have both villi and microvilli, which are small finger-like projections off of the cells. These villi and microvilli play a vital role in the absorption of food passing through the small intestine. What best explains why these projections play such a vital role in the intestinal cells?
They increase the surface area to volume ratio
(for food absorbtion)
What is the best explanation for why the meniscus of water in the capillary tube to the right is concave?
The adhesive forces are stronger than the cohesive forces
You are given a protein with the following amino acid sequence:
methionine (nonpolar)-glycine (nonpolar)-serine (polar)-alanine (nonpolar)-lysine (polar)
If an amino acid substitution occurred in this polypeptide chain, how would that affect the structure and function of the protein?
Replacing a polar amino acid with a nonpolar amino acid would greatly affect the structure of the protein, therefore greatly affecting the function
Glucose serves as nutrients and fuel for cells. In which process is glucose used?
Cellular respiration
Which macromolecule stores hereditary information?
Nucleic acid
Which macromolecule comprises a major portion of the plasma membrane?
(Phospho)lipids
Which macromolecule monomers come together through the formation of peptide bonds?
Proteins
A researcher is studying the movement of a protein that is secreted from a eukaryotic cell. Which pathway best represents the movement she could expect for packaging/processing of the secretory protein?
Rough ER -> Golgi Apparatus -> Secretory Vesicles -> Cell Membrane
Explain how both the mitochondria and golgi complex are highly efficient in their functions.
Both organelles have compartmentalization and many folds increasing surface area
One difference between plant and animal cells is that plant cells have what organelles?
A large central vacuole, chloroplast, cell wall
The NaCl concentration of red blood cells is 154mM. Predict what would happen if the cell was placed in a 220mM NaCl solution.
The red blood cell would shrink
The NaCl concentration of red blood cells is 155mM. Predict what would happen if the cell was placed in a 93mM NaCl solution.
The red blood cell would swell
What does it mean to say that phospholipids are amphipathic?
They have both hydrophilic and hydrophobic parts
Contrast prokaryotes and eukaryotes.
Prokaryotes: No membrane bound organelles, no nucleus, bacteria
Eukaryotes: Membrane bound organelles, have a nucleus, all other living things
A plant species that has a chromosome number, n, of 2n = 30. What number of chromosomes would the eggs of this plant contain?
15
What type of molecules can do simple diffusion, due to their size through the cell membrane?
Small nonpolar molecules and small polar molecules
What type of molecules can pass through the cell membrane by diffusion and do not need any assistance?
Nonpolar hydrophobic molecules
What type of molecule can do simple diffusion because they are small and uncharged?
Gases
What type of molecule will do facilitated diffusion because molecules like glucose need help passing through the membrane?
Large polar molecules
What are the monomers and polymers of Carbohydrates?
Monosaccharides and Polysaccharides, respectively
What are the monomers and polymers of Proteins?
Amino Acids and Polypeptides, respectively
What are the monomers and polymers of Lipids?
Fatty acids and glycerol (monomers), yet there are no true polymers
What are the monomers and polymers of Nucleic Acids?
Nucleotides and Polynucleotides, respectively
What are the substances that participate in a chemical reaction called?
Reactants (substrates)
During a chemical reaction, bonds must first be broken in the reactant molecules. The amount of energy required to break these bonds is called what?
Activation energy
What are enzymes and what do they do?
They are proteins that speed up chemical reactions by lowering the activation energy needed for the reaction.
Are enzymes reusable?
Yes
Which group of compounds do enzymes belong to?
Proteins
What do enzymes do for the activation energy for chemical reactions occurring in living cells?
They lower it
What are organic substances that speed up the chemical reactions of the cell?
Enzymes
What is a pocket or groove on the surface of an enzyme into which the substrate molecules fits?
Active site
What is the initial investment of energy needed to start a chemical reaction?
Activation energy
What name is given to an inorganic substance that speeds up a chemical reaction?
Catalysts
What would happen to the chemical reactions in living cells if enzymes were not present?
They would happen so slowly it would be of no use to us
Are enzymes substrate specific for the reaction they catalyze?
Yes
