Exam 1 Review (old HW & Quizzes)
A lipid bilayer with SHORT UNSATURATED hydrocarbon tails have ____ fludity and permblity
HIGHER
Which of the following statements best distinguishes hypotheses from theories in science?
Hypotheses usually are relatively narrow in scope; theories have broad explanatory power.
Based on what you know about the Central Dogma of molecular biology, where would you expect RNA transcription to occur in an animal cell?
the cytoplasm the nucleus "Transcription is the conversion of DNA to an RNA copy, or "message." So transcription needs to happen where DNA is located. There is one tricky part to this question. As you discovered in your reading, the mitochondria of a cell also have a mitochondrian genome. So a correct answer will include both the nucleus and the mitochondria."
Bacteria construct an H+ gradient across the plasma membrane, with many more H+ outside of the cell than inside. This gradient is then used to rotate the flagella. What do you predict about this process of constructing the H+ gradient by exporting H+ outside of the cell?
It will take chemical energy (ATP) to transport H+ across the membrane to build the gradient
You add the following to a tube: a plant protein that normally helps hydrolyze the 1,6-Glycosidic linkages in Starch Glycogen What do you predict will happen?
the protein will be able to help hydrolyze at least some of the glycogen, which has a very similar structure with the same 1,6-Glycosidic linkages.
Which of the following relationships between cell structures and their respective functions is NOT correct? rough endoplasmic reticulum: protein synthesis chloroplast: photosynthesis mitochondria: formation of ATP peroxisome: energy production in animal cells
Peroxisomes are involved in detoxifying toxins in the cell. Because this often produces hydrogen peroxide, which can damage proteins, lipids, and DNA, peroxisomes have a special enzyme to convert H2O2 to water and oxygen.
A cell wall is a structure present in cells from some species from which of the following taxonomic groups? Plants Bacteria Viruses All animal cells
Plants and bacteria animal cells do not have a cell wall just a plasma membrane
When you observe an unequal sharing of electrons within a bond between two atoms, which of the choices below best describes such a bond?
Polar covalent
peripheral proteins
Protein appendages loosely bound to the surface of the membrane and not embedded in the lipid bilayer.
What packs together more tightly unsaturated fats or saturated fats
Saturated fats pack together more tightly because they don't have double bonds that kink
Which of the following are polymers? glucose starch Either purine Either pyrimidine a polypeptide DNA amino acids
Starch Polypeptide DNA
horizontal gene transfer
The transfer of genes from one genome to another through mechanisms such as transposable elements, plasmid exchange, viral activity, and perhaps fusions of different organisms.
Membranes are semi-fluid, meaning
There is lateral movement of the phospholipids Lipids can rotate on their own axis membrane proteins can move laterally and rotate within the bilayer
What is the role of nuclear pores?
To allow passage of large molecules into and out of the nucleus
Which of the following proteins do you think would pass through the golgi apparatus?
a glycosylated transmembrane protein embedded in the plasma membrane in order to sense a hormone "The golgi modifies proteins (e.g. adds carbohydrates, or "glycosylates"), often before exporting these proteins to the plasma membrane or exterior of the cell."
Anabolism
anabolism is metabolism that builds up molecules (often storing energy in polymer bonds bonds or creating macromolecules the cell needs).
Amphipathic molecules are
both hydrophilic and hydrophobic
Which of the following is an example of catabolism in a typical animal cell?
breakdown of carbohydrates via acid hydrolases in a lysosome
Catabolism
catabolism is metabolism that breaks down molecules (often to gain energy from their bonds or release monomers).
lipid-anchored proteins
covalently attached to a phospholipid or fatty acid embedded in the bilayer
Which of the following structures is exclusive to eukaryotes, meaning you won't find it in bacteria or archaea? a cell wall DNA endomembrane system ribosomes
endomembrane system
saturated fats
fats that are solid at room temperature More tightly packed than unsaturadted fats
vertical gene transfer
flow of genetic information from one generation to the next Traditional evolution Mother to Offsping
Based on subcellular structures of eukaryotic cells, where is protein translation likely to occur?
in the cytosol, sometimes adjacent to the rough ER "Where are the ribosomes? Remember, although ribosomes are formed in the nucleus (at the nucleolus), they are exported to the cytosol to do their work in protein translation."
unsaturated fats
liquid at room temperature Has at least one double bond (kink) Has less hydrogen atoms bonded to the carbons than saturated fats
Which of the following is NOT a part of the endomembrane system? mitochondria peroxisome smooth endoplasmic reticulum (smooth ER) lysosome
mitcochrondiron
passive diffusion
movement of substances across a semipermeable membrane with the concentration gradient; this process does not require energy
Which of the following is an example of anabolism in a typical animal cell?
ormation of glycogen from glucose
Ricin is a protein toxin produced naturally by plants. Small doses of ricin can kill humans. Ricin acts by inhibiting protein synthesis in target cells. Based on what you know, which of the following strucutres or organelles might be the most likely target of ricin?
ribosomes. They are where protein is made
Which of the following best describes the route that an extracellular protein would take if it was being translated and then secreted out of the cell through the endomembrane system?
rough endoplasmic reticulum→ Golgi apparatus→vesicles →plasma membrane
osmotic lysis
rupture of the plasma membrane resulting from movement of water into the cell
horizontal gene transfer (HGT)
(also, lateral gene transfer) transfer of genes between unrelated species
The three domains of life that represent all living organisms are the _______________________.
Archea bacteria eukarya
Organisms from the domains ______and __________are characteristically smaller, single-celled organisms without a nucleus.
Bacteria and Archea (Prokayaotes)
Which of the molecules below is/are amphipathic? (Select any that are amphipathic)
C B D A
Cell surface to volume ratio
Cells need a large surface area to get food in and waste out. But when a cell gets bigger, the surface to volume ratio decreases so a huge cell can't survive. Many smaller cells work together instead. As cells grow in size, the SA/V ratio decreases quickly, meaning export and import of substances across the plasma membrane becomes too inefficient to support cellular metabolism.
simple diffusion
Diffusion that doesn't involve a direct input of energy or assistance by carrier proteins.
A draft of the first human genome sequence (all 3.2 billion base pairs of DNA) was first finished in 2001, at a cost of several billion dollars. This was an example of
Discovery Based Science
A scientist runs tests on a population of isolated cells belonging to a larger organism. She discovers that a majority of the glucose molecules present within the cells are in the form of highly branched polysaccharides. Based on this discovery, what is the likely function of glucose in those cells of the organism?
Energy Storage
Organisms in which of the following taxonomic groups have a nucleus?
Eukaryotes: Animals Fungi Plants
Unlike Eukaryotes, Bacteria do not have subcellular structures that impart specific function to cells. True or False?
False, because bacteria have subcellular structures such as pili and flagella that impart specific functions such as cell-to-cell communication and motility
Glycogen Starch and Celluso are made of what?
Glucose.
Hydrolysis of which of the following polymers could produce glucose?
Glycogen Starch Cellulose
