Video Notes Review: Calcium in Skeletal Muscle, Cell Transport, Mitosis & Meiosis, Cancer & Genetics

A comprehensive set of practice Q&A flashcards based on the lecture notes, covering calcium in skeletal muscle, cellular transport, mitosis/meiosis, cancer, and basic cell biology.

Which skeletal muscle organelle stores calcium and concentrates it about 70,000 times compared to the cytosol?

Sarcoplasmic reticulum (SR).

What pump uses ATP to move calcium into the sarcoplasmic reticulum?

Ca2+-ATPase (SERCA pump) that pumps Ca2+ into the SR.

Why do skeletal muscles contain many mitochondria?

To provide energy for calcium pumping and muscle contraction.

What is the Na+/K+ pump’s ion movement per ATP hydrolyzed, and what is its effect on membrane potential?

3 Na+ are pumped out and 2 K+ are pumped in per ATP; the inside becomes more negative (negative resting membrane potential).

In the Na+/K+ pump, where do sodium and potassium ions move?

Sodium moves to the extracellular fluid; potassium moves into the cell.

What is exocytosis?

Release of substances from the cell as vesicles fuse with the plasma membrane.

What is endocytosis and its subtypes mentioned?

Process of taking in material via vesicle formation; includes pinocytosis (fluid uptake) and phagocytosis (cell eating).

What is pinocytosis?

Fluid-phase endocytosis; the cell engulfs extracellular fluid.

What is phagocytosis?

Engulfment of large particles (e.g., bacteria) by extending pseudopods; vesicles fuse with lysosomes for digestion.

Which organelle contains enzymes that digest engulfed material in phagocytosis?

Lysosome.

What is the difference between chromatin and chromosomes?

Chromatin is uncondensed DNA; chromosomes are condensed, visible DNA during mitosis.

What are sister chromatids?

Identical copies of a chromosome held at the centromere; separated during anaphase.

What is a centromere?

The region where sister chromatids are attached and where spindle fibers attach during mitosis.

What are centrioles and spindle fibers responsible for?

Centrioles organize the spindle; spindle fibers attach to centromeres to separate chromatids.

What happens during prophase of mitosis?

Chromosomes condense; nucleolus disappears; nuclear envelope dissolves; spindle apparatus forms.

What happens during metaphase of mitosis?

Chromosomes align at the metaphase plate; spindle fibers attach to centromeres.

What happens during anaphase of mitosis?

Sister chromatids separate and are pulled toward opposite poles.

What happens during telophase and cytokinesis?

Nuclear envelope reforms; chromosomes de-condense; cytoplasm divides (cytokinesis); cleavage furrow forms.

What is the difference between mitosis and meiosis?

Mitosis yields two identical diploid daughter cells; meiosis yields four haploid gametes with half the DNA.

What is a zygote?

A fertilized egg with 46 chromosomes (23 from each parent).

What are homologous chromosomes?

Pairs of chromosomes (one from each parent) with the same genes at the same loci.

What causes Down syndrome as mentioned in the notes?

A 9-21 translocation (as described in the lecture).

What is a benign tumor?

A noninvasive tumor that stays within its original tissue and is usually not life-threatening.

What is a malignant tumor?

A tumor that invades surrounding tissue and can metastasize to distant sites.

What is metastasis?

Spread of cancer cells through the bloodstream or lymphatic system to other parts of the body.

What is neoplasm?

An abnormal new growth of tissue; a tumor.

What are common cancer treatments mentioned in the notes?

Chemotherapy, radiation therapy, surgery, and immunotherapy (including emerging dendritic-cell approaches).

Where do breast tissues drain lymphatically?

Axillary lymph nodes.

Which organelle makes lipids and steroid hormones?

Smooth endoplasmic reticulum (Smooth ER).

Which organelle makes proteins and has ribosomes on its surface?

Rough endoplasmic reticulum (Rough ER).

What is the role of histones?

Proteins around which DNA wraps to form nucleosomes and package DNA into chromosomes.

What are the three components of a nucleotide?

Sugar (deoxyribose or ribose), phosphate group, and a nitrogenous base.

What is the primary function of mitochondria and their genetic material?

Powerhouse of the cell; produce ATP and contain their own DNA (about 37 genes) and ribosomes, supporting endosymbiotic theory.

Do mature red blood cells have a nucleus and DNA?

No; mature RBCs lack a nucleus and DNA, contributing to a ~90–120 day lifespan.

What is the general equation for cellular respiration with oxygen?

Glucose + O2 → CO2 + H2O + ~38 ATP + heat.

Why does CO2 increase in blood lead to acidity?

CO2 reacts with water to form carbonic acid, releasing H+ and lowering pH.

Which body systems handle gas exchange and transport of O2/CO2?

Gas exchange occurs in the respiratory system; transport is via the cardiovascular system.

What structure divides the abdominal and pelvic cavities, as mentioned in the notes?

The diaphragm (as described in the lecture).