Unit 1
Name the sugar & nitrogen bases in DNA and RNA
DNA: deoxyribose; A-T, C-G
RNA: ribose; A-U, C-G
What are differences between a prokaryotic and eukaryotic cell.
Prokaryotic: no nucleus, membrane-bound organelles, smaller (bacteria & archea)
Eukaryotic: has nucleus, has membrane-bound organelles, larger (animals, plants, fungi, protist)
Define ATP
main energy molecule used by cells
What is a ligand?
a molecule that binds to a receptor and initiates a signal
What is the difference between passive and active transport?
Passive: no energy, moves down gradient
Active: needs energy, moves against gradient
Define polarity
a molecule with unequal sharing of electrons, resulting in partial chargers
What is the endosymbiotic theory.
The theory that explains how eukaryotic cells evolved from prokaryotic cells through the incorporation of smaller organisms.
What process occurs when oxygen is not available for cellular respiration?
fermentation
What is a hormone? How is it an example of long distance communication?
A chemical messenger released into the bloodstream and travels to distant target cells.
Negative feedback restores conditions back to normal by reversing changes, keeping internal conditions stable.
Describe dehydration synthesis
Monomers join to form a polymer by removing a water molecule as a byproduct.
Which molecules are able to move easily across the plasma membrane?
Small, nonpolar molecules (oxygen, carbon dioxide); lipids
What type of metabolic reaction is cellular respiration?
Exergonic / catabolic
Give 1 example of negative feedback and 1 example of positive feedback
Positive Feedback: labor
Which organelle is responsible for modifying and shipping cell products?
Golgi apparatus
The attraction between molecules of the same kind is called _______. The hydrogen bond between the two water molecules are found between the _____________________________________.
cohesion; partial positive hydrogen and partial negative oxygen of another molecule.
What 2 organelles are thought to have been early prokaryotes engulfed by a eukaryotic cell? What else do they have in common?
Mitochondira & Chloroplast
Common traits: have their own DNA, double membrane, reproduce through binary fission, have their own ribosomes
Explain the process of feedback inhibition
When the end of the product of a metabolic pathway binds to the first enzyme and shuts the pathway off to prevent overproduction
How are plasmodesmata examples of direct contact between cells?
They are channels between plant cells that allow molcules and signals to pass directly from cell to cell.
Define covalent bond
a bond between 2 nonmentals to share electrons
For each biomolecule name their monomer, give one example, and function.
Carbohydrates: Monosaccharides; Glucose, Starch; energy, structure
Lipids: Fatty acids + Glycerol; fats, oils, phospholipids; energy, storagem mambranes
Proteins: Amino Acids; enzymes; structure, catalysis
Nucleic Acids: Nucleotides; DNA, RNA; store genetic information
Calculate the Surface area to volume ratio for the following cells.
Cell A: SA = 15; V = 3
Cell B: SA = 27; V = 3
Cell C: SA = 39; V = 13
Which cell is more efficient at exchanging materials with their environment? Why?
Cell B because it has the highest SA/V ratio = best at exchanging materials.
The larger the cell is, the lower its SA/V ratio, which means it's less efficient at exchanging materials.
Identify the type of metabolic reaction that is coupled with the following:
a. the synthesis of ATP
b. the hydrolysis of ATP
a. endergonic (requires energy)
b. exergonic (releases energy)
What is bacteria quorum sensing?
A communication process where bacteria detect population density and coordinate behaviors.
What is the advange of eukaryotic cells having internal membranes?
create compartments for specialized functions = increased efficiency