Week 2 Day 3 Notes — Movement Across Cell Membranes and The Cell Cycle

A comprehensive set of practice flashcards covering membrane transport, osmosis, endocytosis/exocytosis, the cell cycle and mitosis, apoptosis, and cancer-related genes based on Week 2 Day 3 notes.

Does active transport require energy?

Active transport requires energy (ATP) ADENOSINE TRIPHOSPHATE

What are the 3 types of passive transport and do they require energy?

Diffusion, facilitated Diffusion & osmosis

Passive transport does not require energy

What is diffusion? Does temperature affect its rate ?

Diffusion is the movement of molecules from high to low concentration.

Temperature determines the rate of diffusion the highter the temp the faster the rate

What is facilitated diffusion?

Facilitated diffusion uses carrier proteins to transport substances without energy.

What is osmosis?

Osmosis is the movement of water across a selectively permeable membrane from higher water concentration to lower.

What is tonicity?

Tonicity is the ability of a solution outside the cell to alter the cell's water volume.

Define isotonic solution.

An isotonic solution has the same osmotic pressure as inside the cell, so the cell remains its normal size.

Define hypertonic solution.

A hypertonic solution has higher external osmotic pressure, causing water to leave the cell and the cell to shrink.

Define hypotonic solution.

A hypotonic solution has lower external osmotic pressure, causing water to enter the cell and the cell to swell.

What is osmotic pressure?

Osmotic pressure is the pressure generated by osmosis that can move water and change water levels.

What is filtration?

Filtration is the process of forcing molecules through membranes by exerting pressure

What is endocytosis?

Endocytosis is when a vesicle is produced on the cell membrane to allow moleculesto be brought IN TO the cell

Name and describe the three types of endocytosis.

Pinocytosis: droplets of liquid; Phagocytosis: solid particles; Receptor-mediated endocytosis: specific particles binding to receptors.

What is exocytosis?

Exocytosis is when a vesicle is produced by the endoplasmic recticulum and then sent OUTSIDE the cell

What is transcytosis?

Transcytosis moves in quickly forms a vesicle then moves out of the cell

What is interphase in the cell cycle?

Interphase is the longest phase, the preparation stage, no division occurs.

G1 S G2

What are the stages of mitosis?

Prophase, Metaphase, Anaphase, Telophase (followed by Cytokinesis for cell separation).

What happens during prophase?

Nucleus disappears, genetic material condense and attach to the spindle.

What happens during metaphase?

Attached genetic material moves to the center of the cell.

What happens during anaphase?

Genetic material is pulled apart and moves to opposite ends of the cell.

What happens during telophase?

Spindles disappear & nucleus reappears

What is cytokinesis?

When the cell has completed divided into 2 identical cells

What is apoptosis?

Programmed cell death; activated when a cell is deemed defective by checkpoint signals.

What are oncogenes?

Abnormal, overexpressed versions of genes that regulate the cell cycle, promoting excessive cell division.

What are tumor suppressor genes?

Genes that normally limit mitosis; when inactivated, they fail to regulate cell division.

How do oncogenes and tumor suppressor genes relate to cancer development?

Checkpoints prevent division of defective cells; oncogenes can drive rapid division if not countered by tumor suppressors, leading to tumor formation.

What are the two main types of tumors and their characteristics?

Benign tumors stay local and may enlarge; malignant tumors are invasive, cancerous, and can metastasize.