Cell Bio Exam 3

• 1. β-oxidation lengthens fatty acids by addition of two carbons; True or False?

  False; it is the removal of two carbons
• FADH2 transfers its electron to complex II

  True; it transfers to iron-sulfur proteins in complex II
• 1. The process of gluconeogenesis converts pyruvate or lactate into...
• The Na+/K+-ATPase pump actively moves 2 Na+ out and 3 K+ in 


  This is true!
• Which of the following proteins would be a good drug target for interfering with microfilament network breakdown?

  Gelosin; Gelsolin plays a crucial role in regulating actin filaments by severing them and promoting their disassembly.
• Which technique would be best used to measure the strength of a v-SNARE-t-SNARE interaction?

  Optical tweezers as it allows for better control of force between the two protiens
• Which of the following proteins requires GTP in the process of LDL receptor-mediated endocytosis?

  LDL receptor

  dynamin

  AP-2 complex

  clathrin

  Dynamin
• What is the function of dynamin?

  Dynamin plays a crucial role in pinching off vesicles during endocytosis, including the internalization of low-density lipoproteins (LDLs) via the LDL receptor.
• Which of the following is false about lamellipodia?

  Their formation is stimulated by activation of Rac

  They may have associated filopodia

  They contain bundles of microtubules that push the plasma membrane forward

  They extend at the leading edge of crawling cells

  They contain branched networks of actin filaments

  They contain bundles of microtubules that push the plasma membrane forward
• The plant cell organelle most analogous to animal cell lysosomes is the

  vacuoles
• In which of the organelles would you expect to first find a protein destined to be secreted from a cell?

  Endoplasmic reticulum
• Actin bundles give shape and support to cilia found in intestinal mucosal cells; True or False

  False, actin are not directly correlated to cilia
• How many monomers are microtubules made of?

  Two!
• In C4 plants the rubisco is isolated in the ____ to limit the oxygenase activity

  bundle sheath
• Continuous carbon assimilation in the Calvin cycle is made possible by the regeneration of ribulose-1,5-bisphosphate True or False


  True
• When a photon is absorbed by a pigment (light-absorbing molecule), such as chlorophyll, the energy of the photon is transferred to an electron to move it from a low to a high energy orbital
• Rubisco has a dual enzymatic function: carboxylase/deoxygenase true or false
• Catalyzing the removal of oxygen from RuBP. Although this process is wasteful in terms of energy, it helps prevent the accumulation of toxic compounds.

  deoxygenase function of rubisco
• Catalyzes the addition of carbon dioxide (CO₂) to ribulose-1,5-bisphosphate (RuBP) during the Calvin cycle (also known as the C3 photosynthesis pathway).

  Carboxylase function of rubisco
• Protein glycosylation in the endoplasmic reticulum (ER) begins with a molecule called dolichol phosphate.
• Calnexin and calreticulin helps in the proper folding of glycoproteins synthesize in ER True or False


  True
• In a lysosomal storage disease, newly synthesized lysosome hydrolases are secreted from the cells rather than being delivered to the lysosomes. What is one possible mechanism for this result?

  Mannose is not phosphorylated in the cis Golgi network
• The vesicles of receptor mediated endocytosis are covered with 

  They are coated with a protein called clathrin on the cytoplasmic side of the plasma membrane.
• true or false: Plastocyanin is a mobile electron transport giving its electron to ferrodoxin NADP reductase

  true
• The Hath-Slack cycle occurs in

  bundle sheath cells
• Rac is involved in the polymerizatin of microtubules True or False


  True, Rac1
• Colchicine affects microtubules assembly by ____ their assembly

  Preventing
• Actin bundles give shape and support to the

  microvilli
• Disulfide bonds are often found to stabilize secondary protein structure True or False

  True
• Caveolin coated vesicles origination from the plasma membrane True or False


  true
• Actin filaments may form each of the following except

  3D filament networks (gels)

  contractile bundles

  branched networks

  bundles of parallel filaments

  axonemes containing doublet microfilaments

  axonemes containing doublet microfilaments
• Which of the following is the site of photosynthesis in cyanobacteria?

  peroxisomes

  mitochondria

  photosynthetic membranes

  outer walls

  thylakoid lumens

  thylakoid lumens
• The smooth endoplasmic reticulum functions in synthesis of

  lipids and calcium storage
• The hallmark feature of peroxisomal diseases is the accumulation of

  very long chain of fatty acids
• Which of the following enzyme is not involved in the regulation of the citric acid cycle?

  isocitrate dehydrogenase

  alpha ketoglutarate  dehydrogenase

  Malate dehydrogenase

  succinate  dehydrogenase

  all  above are involved in the regulation of citric acid cycle

  succinate  dehydrogenase
• Pyruvate dehydrogenase is regulated by all of the following except

  ATP

  CO2

  NADH

  Acetyl CoA

  CO2
• In a lysosomal storage disease, newly synthesized lysosome hydrolases are secreted from the cells rather than being delivered to the lysosomes. What is one possible mechanism for this result?

  The cis-Golgi network lacks a proton gradient

  The ER is unable to produce lysosomal vesicles

  Lysosomal enzymes are not phosphorylated in the rER

  Mannose is not phosphorylated in the cis-Golgi network

  All the hydrolase genes are mutated, resulting in synthesis by ribosomes free in the cytoplasm rather than on the endoplasmic reticulum membrane

  Mannose is not phosphorylated in the cis-Golgi network
• Each of the following is part of the core oligosaccharide side chain in the ER except

  N-acetyl glucosamine

  erythrose

  mannose

  glucose

  All are part of the core oligosaccharide

  erythrose
• Which of the following types of organisms makes use of the Hatch–Slack cycle?

  c4 plants
• The Calvin cycle occurs in thechloroplast

  stroma

  grana thylakoid

  lumen outer membrane

  thylakoid membrane

  stroma