General Biology: Cellular Processes & Bioenergetics Examination Review

Comprehensive practice flashcards covering photosynthesis, cellular respiration, fermentation, bioenergetics, enzyme kinetics, cell signaling, and membrane transport based on the Biology exam review.

Where inside a chloroplast is fluorescently tagged organic carbon most likely to be found in high concentration?

In the stroma.

How many additional membranes must a protein pass after crossing the outer chloroplast membrane to reach the stroma and thylakoid lumen, respectively?

$$2$$

What is required for carbon dioxide ($CO_2$) and water ($H_2O$) to combine and form glucose, water, and oxygen?

Light energy from the sun.

What are the flattened sacs of internal membranes associated with photosynthesis called?

Thylakoids.

What term describes clusters of chlorophyll and accessory pigments embedded within membranes?

Photosystems.

In green plants, which photosystems absorb photons to excite electrons in the reaction center?

Photosystem I and II.

Which substance is NOT an input required by the Calvin cycle?

Oxygen ($O_2$).

In what type of environment are CAM and C4 plants most likely adapted to grow?

Hot and arid.

What two products are directly generated by the light-dependent reactions of photosynthesis?

ATP and NADPH.

Which wavelength color of light absorbed by chlorophylls carries the highest energy?

Violet-blue.

What are organisms called that depend on chemical energy stored in bonds by other organisms?

Heterotrophs.

Through what pathway do animals break down glucose into $CO_2$ and $H_2O$ using atmospheric oxygen?

Aerobic respiration.

In glycolysis, in which final product does a major portion of glucose's chemical energy remain?

Pyruvate.

Within which organelle location does pyruvate oxidation occur in eukaryotic cells?

Mitochondria.

What metabolic intermediate are dietary fats primarily converted into for cellular energy?

Acetyl-CoA.

Regardless of the final electron acceptor used, what is always an essential product of fermentation?

$$NAD^+$$

Which metabolic pathway is evolutionary conserved and common to all living cells?

Glycolysis.

Which stage of cellular respiration is most directly impaired by iron deficiency anemia affecting central heme groups?

Electron transport chain.

Why are electron transport chain components embedded in the inner mitochondrial membrane instead of floating freely?

To establish and maintain a proton gradient for ATP production.

What feature is common to all oxidation reactions occurring in the Citric Acid Cycle?

Loss of electrons from organic molecules coupled to electron acceptor reduction.

What physical entities are transferred, gained, or lost during oxidation-reduction (redox) reactions?

Electrons.

In the reaction $\text{G3P} + NAD^+ \rightarrow \text{1,3-bisphosphoglycerate} + NADH$, what happens to $NAD^+$?

It was reduced.

What term refers to the overall energy in a system available to perform cellular work?

Free energy.

Because the synthesis of sugar requires an input of energy absorbed from sunlight, how is photosynthesis classified thermodynamically?

Endergonic.

What type of inhibitor binds directly to an enzyme's active site and prevents substrate binding?

Competitive inhibitor.

At what temperatures do human enzymes and thermal prokaryote enzymes typically reach their optimal activity?

$40\,^\circ\text{C}$ and $72\,^\circ\text{C}$, respectively.

Why is ATP considered the primary energy currency of cellular metabolism?

Phosphate bonds are unstable and release energy upon cleavage.

How are anabolic and catabolic metabolic pathways classified regarding energy change?

Anabolic pathways are endergonic; catabolic pathways are exergonic.

What does the observation that glycolysis occurs in nearly all cells while the Krebs cycle is more restricted indicate about their evolutionary history?

Glycolysis evolved prior to the Krebs cycle.

What is the total sum of all chemical reactions occurring within a living organism called?

Metabolism.

Direct transmission of second messengers between adjacent cells via gap junctions represents what type of signaling?

Direct contact signaling.

Why are phosphorylation and dephosphorylation steps frequently used in signaling cascades?

Adding or removing phosphate alters protein shape and binding activity.

In synaptic signaling, across what specialized space do neurotransmitters diffuse?

Chemical synapse.

A drug that blocks localized signaling between non-metastatic neighbor tumor cells targets which type of signaling?

Paracrine signaling.

What does inhibiting a channel-linked membrane receptor directly prevent?

Ligand binding to receptor.

Which molecules directly convert extracellular ligand binding into intracellular signals?

Membrane receptors.

Because mitogen-activated protein kinase (MAPK) phosphorylates target proteins, MAPK functions as a(n):

Enzyme.

What shared functional capability is common to both GPCRs and Receptor Tyrosine Kinases (RTKs)?

Ability to activate Phospholipase C.

A mutation in the DNA-binding domain of a steroid hormone receptor directly impacts which functional output?

Downstream cellular response/transcription.

The plasma membrane consists of a phospholipid bilayer embedded primarily with which macromolecules?

Proteins.

What structure is required for the passive net movement of water (osmosis) to occur?

A semipermeable membrane.

What is the carrier-mediated diffusion of a substance down its concentration gradient without energy expenditure called?

Facilitated diffusion.

What structure mechanically counteracts osmotic turgor pressure in plants, fungi, and bacteria?

Cell wall.

What mode of transport moves a solute against its concentration gradient driven by ATP hydrolytic energy?

Active transport.

During one single active cycle of the $Na^+/K^+$ pump powered by $1$ ATP molecule, what ions are moved across the membrane?

$3\,Na^+$ exit and $2\,K^+$ enter.

Why do transmembrane proteins remain anchored inside lipid bilayers?

Because interior amino acids are hydrophobic.

What property describes the amino acids comprising protein segments that span the central core of phospholipid bilayers?

Nonpolar.

Internalization of transferrin via specialized clathrin-coated pits is classified under which transport process?

Receptor-mediated endocytosis.

What process refers to the cellular engulfment of large particulate matter or whole microorganisms ("cellular eating")?

Phagocytosis.