exam 2 (practice questions) Flashcards
why should you use a light microscope if you want to film the movement of chromosomes during cell division?
because the specimen is alive
- although light microscopes have far less resolution than electron microscopes, light microscopy is the only technique that permits one to observe living cells
what is cell fractionation?
laboratory technique that is used to separate the various components of cells
(like taking apart a cell to examine the little pieces of it)
two cells have the same volume but different surface areas. the cell with the larger surface area is likely to ______________
be involved in the rapid uptake of compounds from their cell’s environment
in cells, the greater the surface area, the greater the ______________
potential for transport
name 3 things that are likely to limit the maximum size of a cell
- cell’s surface-to-volume ratio
- time it takes a molecule to diffuse across a cell
- shape of the cell
(mainly the surface-to volume ratio) and everything else just kinda means the same thing)
do prokaryotic cells contain the following organelles:?
- mitochondria
- ribosomes
- plasma membrane
- cytosol
- DNA
- nucleus
- no, only eukaryotic cells have membrane bound organelles
- yes, ribosomes are required for protein synthesis and present in both types of cells
- yes, all cells have plasma membranes
- yes, volume enclosed by plasma membrane in prokaryotic cells is the cytosol
- yes, all living cells contain DNA
- no, prokaryotes are named for their lack of a nucleus
A substance moving from outside the cell into the cytoplasm must pass through __________
the plasma membrane
In terms of cellular function, what is the most important difference between prokaryotic and eukaryotic cells?
eukaryotic cells are compartmentalized (due to the presence of membrane-bound organelles) , which allows for specialization
which 3 features do prokaryotes and eukaryotes have in common?
ribosomes, plasma membrane, and cytoplasm
protists cells are ___________ that can ___________
eukaryotes; photosynthesize
What is the functional connection between the nucleolus, nuclear pores, and the nuclear membrane?
proteins and ribosomes are assembled in the nucleolus and pass through the nuclear membrane via the nuclear pores
when do chromosomes appear in an obvious form in the cell?
although they appear more compact as the cell prepares to divide, they are always present in the cell, even when cells are not actively synthesizing proteins
where is DNA housed?
in the nucleus
which 3 groups of organelles are mainly involved in synthesizing molecules needed by the cell?
ribosomes, rough ER, smooth ER
function of the rough endoplasmic reticulum
manufacture of proteins for the end-membrane system
function of the smooth endoplasmic reticulum
synthesis of essential lipids such as phospholipids and cholesterol
function of the Golgi apparatus
further modify and sort the lipids and proteins produced by the ERs and prepare them for their destinations in either lysosomes, plasma membrane, or excretion
You would expect a cell with an extensive Golgi apparatus to __________
secrete large amounts of protein
function of vesicles
carry and transport material that the cell needs
transmembrane proteins vs. soluble proteins
transmembrane proteins: proteins embedded within cell membrane, allows them to interact with both inside and outside of the cell
- play roles in cell communication, transport of molecules across membrane, and structural support for membrane
soluble proteins: found in watery parts of cell, like cytoplasm or nucleus and are not embedded within membranes
- have various functions like catalyzing chemical reactions, providing structural support, and acting as messengers or signals within the cell
transmembrane proteins are “anchored”, soluble proteins are “floating”
A protein that ultimately functions in the plasma membrane of a cell is most likely to have been synthesized __________
in the rough ER
all of the membrane proteins of the endomembrane systems are made in the rough ER
why is the mitochondrial outer membrane have a lipid composition that is different from the lipid composition of other cells?
mitochondria are not part of the endomembrane system and must synthesize their own lipids
chloroplasts and mitochondria are similar in the way that they ______________
synthesize their own proteins
chloroplasts and mitochondria can synthesize some of their own proteins because they contain DNA and ribosomes
which type of cell would be most likely to have the largest number of mitochondria?
cells with the highest energy demand (such as muscle cells in the legs of a marathon runner)
where are the ribosomes of a mitochondria found?
in the matrix
the folds of the inner mitochondrial membrane are called _________
cristae
true or false: mitochondria have more than one membrane
true
microtubules and microfilaments commonly work with which organelle to perform many of their functions?
Golgi apparatus
microtubules guide vesicles from the ER to the Golgi and from the Golgi to the plasma membrane
function of centrioles
only found in animal cells
- play a key role in cell division
- help organize and guide the movement of chromosomes during cell division
- essential for growth and repair of tissues in the body
microtubules
provide structural support to cell and serve as tracks for moving materials
think of them as the highways of the cell
- long, hollow tubes made of protein subunits called tubulin
microfilaments
responsible for movement and shape changes
like the cell’s muscles
- thin, thread-like structures responsible for movement, including cell contraction in animals
intermediate filaments
provide mechanical support and stability to cells, helping them maintain their shape and resist physical stress
think of as “structural cables” of the cell
- type of protein fiber
- resist stretching
Cilia and flagella move due to the interaction of the cytoskeleton with which of the following?
motor proteins
motor proteins
- “movers” of the cell
- specialized proteins that use energy to transport various materials
- play critical role in movement of cilia and flagella
Basal bodies are most closely associated with which cell components?
cilia
microtubule assembly of cilium or flagella is anchored in the cell of a basal body
Dye injected into a plant cell might be able to enter an adjacent cell through __________
plasmodesmata
plasmodesmata
known for role in facilitating communication and transport between PLANT cells
- connect neighboring plant cells, allowing them to exchange various molecules
tight junctions & gap junctions
tight junctions: create barriers/tight seal and control passage of substance between cells
- ex. no fluid leaks b/w cells b/c of them
gap junctions: channels that allow direct communication b/w cells by allowing exchange of ions, small molecules, and signaling (essential for coordination & communication)
Which statement correctly describes a common characteristic of a plant cell wall and an animal cell extracellular matrix?
both are permeable to water and small solutes
substrate-level phosphorylation
process in which a phosphate group is transferred from a high-energy substrate directly to ADP, forming ATP
- occurs in both glycolysis and citric acid cycle
(not in oxidative phosphorylation, aka ETC, b/c that is indirect creation of ATP)
relationship b/w reduction/oxidation and potential energy
- reduced: loses potential energy (moves to a lower energy state)
- oxidized: gains potential energy (moves to a higher energy state)
H+ atom losing or gaining is synonymous with (in terms of reduction and oxidation)
electron
NAD+ is reduced to NADH during which cycles?
glycolysis, pyruvate oxidation, and the citric acid cycle
why are carbs and fats frequently considered high-energy foods?
they contain many electrons associated with hydrogen atoms
substrate-level phosphorylation accounts for approximately what % of ATP formed by the reactions of glycolysis?
100%
what is the NET production of glycolysis?
2 NADH, 2 pyruvate, and 2 ATP
during which metabolic process is MOST of the CO2 from the catabolism of glucose released?
oxidation of pyruvate to acetyl-coA
which electron carriers function in the citric acid cycle?
NADH and FADH2
what is formed by the removal of a carbon from a molecule of pyruvate?
acetyl CoA
true or false: ETC consists of a series of redox reactions
true
which sequence describes the path by which electrons travel downhill energetically in aerobic respiration?
glucose → NADH → electron transport chain → oxygen
the synthesis of ATP by oxidative phosphorylation, using the energy released by the movement of protons across the membrane down their electrochemical gradient, is an example of which process?
coupling of an endergonic reaction to an exergonic reaction
a person who follows a strict diet and loses an excessive amount of weight lost the fat as?
CO2 and H2O
the immediate energy source that drives ATP synthesis by ATP synthase during oxidative phosphorylation is the
H+ concentration gradient across the membrane holding ATP synthase
in mitochondria, exergonic redox reactions
are coupled via phosphorylated intermediates to endergonic processes
when electrons flow along the ETC of mitochondria, what happens to the pH of the matrix?
it increases
most CO2 from catabolism is released during
the citric acid cycle
in autotrophic bacteria, where is chlorophyll located?
in folded regions of the plasma membrane
the oxygen released by photosynthesis is produced by which of the following processes?
splitting water molecules
what happens to the free energy released as electrons are passed from photosystem II to photosystem I through a series of electron carriers?
it is used to establish and maintain a proton gradient
which molecule is the final electron acceptor for electrons from photosystem I?
CO2
what process is directly associated with photosystem I?
receiving electrons from the thylakoid membrane ETC
what is unique about the cyclic electron flow compared to the linear electron flow?
cyclic electron flow uses photosystem I ONLY
- produced ATP, but not NADPH or oxygen
where are ATP synthase complexes located in plant cells?
thylakoid membrane and inner mitochondrial membrane
