Carmen Quizzes Flashcards
Which of the following is NOT true of all living things?
They need oxygen for respiration.
however: They can transfer and transform energy. They are made up of carbon-based organic molecules. They can grow and reproduce. They respond to their environment.
Which one of the following molecules is responsible for both the unity and diversity of life?
DNA
Biology’s core theme of evolution explains traits shared by present day organisms are a result of ________ and traits that differ as evidence of ________.
decent from a common ancester… natural selection
Many of the properties of water are a result of water molecules being able to form hydrogen bonds with _____
compounds that have polar covalent bonds
Stanley Miller’s 1953 experiments support the hypothesis that _____.
organic molecules can be synthesized abiotically under conditions that may have existed on early Earth
Why is carbon so important for biological molecules and their functions?
It can form a variety of carbon skeletons and host a variety of functional groups.
Which functional group(s) shown above is (are) found in all amino acids, the building blocks of protein?
COOH and NH2
Which of the following best summarizes the relationship between dehydration reactions and hydrolysis?
Dehydration reactions assemble polymers; hydrolysis reactions break polymers apart.
Saturated fatty acid ______.
are the principal molecules found in lard and butter
Nucleic acids are molecular polymers made up of which of the following monomers?
nucleotides
What makes carbohydrates and lipids excellent molecules to store energy?
numerous, stable C-C and C-H bonds
Which of the following statements is FALSE? Unsaturated fats _____.
contain more hydrogens than saturated fats with the same number of carbon atoms
however:
are usually liquid at room temperature
are commonly found in plants
have double bonds in their fatty acid chains
If you disrupt all the hydrogen bonds of a protein, which level of protein structure will still be preserved?
primary
If a DNA sample were composed of 20% guanine, what would be the percentage of thymine?
30
Watson and Crick’s model of DNA was different from other scientists’ previous models because in their model
the bases were paired and placed on the interior of the helix and the strands ran in opposite direction.
Which of the following are nucleic acid polymers needed for translation?
mRNA, tRNA, and ribosomal RNA
A plant cell’s DNA can be found in all the following, except:
nucleoid
it can be found in:
a membrane enclosed nucleus
mitochondria
chloroplasts
What is the most likely pathway taken by a newly synthesized protein that will be secreted by a cell?
ER → Golgi → vesicles that fuse with plasma membrane
A young child is suffering from a metabolic disease and is often tired and fatigued. Which of the following organelles is most likely malfunctioning and causing this disease?
mitochondria
The cytoskeleton is directly needed for all the following cell functions or structures, except
glycosylation
it is needed for: cell junctions trafficking of organelles and vesicles cell mobility phagocytosis
Cells need many items to be viable, but across the diversity of cells there are many components that are not essential. Which of the following items is least essential to a cell and so can be absent from the cells of some species?
mitochondria
Which structure-function pair is mismatched?
smooth ER; translation of membrane-bound proteins
correctly matched: centrosome; assembly of microtubules ribosome; translation nucleolus; transcription of ribosomal RNA Golgi; glycosylation
Which type of cell would be best for studying the lysosome?
phagocytic macrophage cells of the immune system
Researchers trying explain how vesicular transport occurs in cells attempted to assemble the transport components. They set up microtubular tracks along which vesicles could be transported, and they added vesicles and ATP (because they knew the transport process requires energy). Yet, when they put everything together, there was no movement or transport of vesicles. What were they missing?
motor proteins
Amoebae move by crawling over a surface (cell crawling), which involves _____.
growth of actin filaments to form bulges in the plasma membrane
Where would you expect to find plasmodesmata?
between plant cells
Which of the following processes involves a solute moving across the membrane AGAINST its concentration gradient?
co-transport
What will happen to a red blood cell (RBC), which has an internal ion concentration of about 1.2 percent, if it is placed into a beaker of pure water?
The cell would swell because the water in the beaker is hypotonic relative to the cytoplasm of the RBC.
Which term most precisely describes the cellular process of breaking down large molecules into smaller ones?
catabolism
Which of the following is a statement of the first law of thermodynamics?
energy isn’t created or destroyed
What kinds of molecules pass through cell membranes most easily (unassisted)?
small and hydrophobic
Relative to bacteria that live in the arctic, the membranes of bacteria found near the oceans’ thermal vents _________.
contain a higher percentage of saturated phospholipids
Which of these are NOT embedded in the hydrophobic portion of the lipid bilayer?
peripheral proteins
these are embedded:
ion channels
integral proteins
transmembrane proteins
Transport across which of the following would NOT change a cell’s membrane potential?
aquaporins
Which of the following reactions types will decrease the entropy in the cell?
anabolic
When ATP releases energy, it also releases inorganic phosphate. What happens to this inorganic phosphate in the cell?
It may be used to form a phosphorylated intermediate.
The metabolic pathway for making the amino acid alanine involves the enzyme pyruvate kinase. Alanine itself is able to bind pyruvate kinase at a site separate from the enzyme’s active site and inhibit its activity. This is an example of all the following, EXCEPT
competitive inhibition
During aerobic respiration, electrons travel energetically downhill in the following sequence:
glucose → NADH → electron transport chain → oxygen
Substrate-level phosphorylation accounts for approximately what percentage of the ATP formed by the reactions of glycolysis?
100%
During fermentation, pyruvate (or a pyruvate derivative) is _________ as it _________ NADH to generate NAD+ for glycolysis.
reduced… gains electrons from
If the thylakoid membrane is damaged such that the interior of the thylakoid becomes permeable to the stroma, which of the following will most directly be affected?
ATP synthesis via photophosphorylation
Which of the following is NOT part of the light reactions of photosynthesis?
oxidation of NADPH and reduction of a 3-carbon intermediate
In photosynthesis, the cyclic flow of electrons involves
synthesis of ATP
How many glucose molecules can be formed from 16 simultaneous turns of the Calvin cycle?
2
Specialized organs release hormones into the bloodstream as chemical signals that can affect target cells. For the target cell to produce a response to a specific hormone, it must _____.
have receptors that recognize and bind the hormone molecule
If a cell was no longer able to produce GTP, what might happen to its signaling system?
It would not be able to activate and inactivate G proteins on the cytoplasmic side of the plasma membrane.
The “threshold” potential of a nerve cell membrane is the _____.
minimum depolarization needed to operate the voltage-gated sodium channels
