Introduction to Biological Sciences I - Biological Membranes

These flashcards cover key concepts related to biological membranes and cellular processes discussed in the lecture.

How do yeast cells obtain glucose?

through the plasma membrane via enzymes like α-glucosidase and through fermentation.

What happens if a yeast cell runs out of ATP?

Maltose transport into the cell will slow down and eventually stop.

What occurs if glucose molecules accumulate in the cytoplasm of a yeast cell?

Water will diffuse out of the cell, and the cell may shrink.

What is tonicity?

the ability of a surrounding solution to cause a cell to gain or lose water.

What is hypertonic solution?

 has a greater solute concentration than that inside the cell, causing the cell to lose water.

How does CO2 produced by fermentation leave the yeast cell?

simple diffusion.

What is exocytosis?

process where transport vesicles migrate to the membrane, fuse with it, and release their contents.

What is phagocytosis?

is a type of endocytosis known as 'cellular eating', where the cell engulfs large particles.

What is paracrine signaling?

involves a signaling cell acting on nearby target cells by secreting local regulators.

What occurs during signal transduction?

converts an extracellular signal into an intracellular signal, often involving receptor activation.

What is the effect of genetic mutations increasing receptor numbers in cancer cells?

increased receptor numbers for Receptor X will divide at an increased rate after ligand binding.

What are G-protein-coupled receptors (GPCRs)?

are membrane-bound receptors that activate heterotrimeric G proteins and bind guanine nucleotides.

What regulates protein activity in phosphorylation cascades?

Protein kinases and protein phosphatases 

What is the end response of a signal transduction pathway?

 change in gene expression, either turning on or off a particular gene.