Cells

According to cell theory, what is considered the structural and functional unit of life?

The cell.

The concept that biochemical functions are determined by a cell's shape and its specific subcellular structures is known as the _____.

Principle of Complementarity of Structure and Function

How many different types of human cells are estimated to exist?

Over 250 types.

What are the three basic parts of a generalized human cell?

The plasma membrane, cytoplasm, and nucleus.

What term describes the extracellular fluid in which cells are submerged or 'bathed'?

Interstitial fluid.

Which extracellular material acts as a 'glue' to hold cells together into tissues?

The extracellular matrix.

The _____ is a flexible lipid bilayer that separates intracellular fluid from extracellular fluid.

plasma membrane

What percentage of membrane lipids are composed of phospholipids?

$75\%$.

Which part of a phospholipid is polar (charged) and hydrophilic?

The phosphate head.

Which part of a phospholipid is nonpolar (uncharged) and hydrophobic?

The fatty acid tail.

What is the function of the cholesterol found within the plasma membrane?

It increases membrane stability.

_____ proteins are firmly inserted into the membrane and typically span the entire bilayer as transmembrane proteins.

Integral

Where are peripheral proteins typically located in relation to the plasma membrane?

They are loosely attached to integral proteins on the membrane surface.

What is the 'sugar coating' on the cell surface that serves as a biological marker for cell recognition?

The glycocalyx.

Which type of cell junction forms an impermeable seal that encircles the whole cell to prevent fluid leakage?

Tight junctions.

Which rivet-like junction allows for 'give' and reduces the chance of tissue tearing under tension?

Desmosomes.

_____ junctions are transmembrane protein tunnels (connexons) that allow the passage of ions and small molecules between cells.

Gap

Which type of membrane transport requires no energy ($ATP$) input from the cell?

Passive transport.

In diffusion, molecules move naturally from an area of _____ concentration to an area of _____ concentration.

high; low

What three factors influence the speed of diffusion?

Concentration gradient steepness, molecular size, and temperature.

What type of diffusion involves nonpolar, lipid-soluble substances passing directly through the phospholipid bilayer?

Simple diffusion.

How does facilitated diffusion differ from simple diffusion?

It requires the assistance of carrier proteins or water-filled channel proteins.

What specific name is given to the diffusion of a solvent, such as water, across a selectively permeable membrane?

Osmosis.

What are the transmembrane water channels called?

Aquaporins.

_____ is a measure of the total concentration of solute particles in a solvent.

Osmolarity

What happens to the volume of a cell placed in a hypertonic solution?

The cell loses water and shrinks (crenation).

What happens to the volume of a cell placed in a hypotonic solution?

The cell takes in water and swells (potential lysing).

In an _____ solution, the osmolarity is the same as inside the cell, so the cell volume remains unchanged.

isotonic

What is the primary difference between primary and secondary active transport?

Primary uses energy directly from $ATP$ hydrolysis, while secondary uses energy from ionic gradients created by primary transport.

Which type of vesicular transport is referred to as 'cell eating' because it engulfs large solid particles?

Phagocytosis.

Which type of vesicular transport is referred to as 'cell drinking' because it brings in extracellular fluid containing solutes?

Pinocytosis.

What is the process called when materials are ejected from a cell via a secretory vesicle?

Exocytosis.

What is the typical range for Resting Membrane Potential (RMP) in human cells?

-10 mV to -100 mV

Which ion is the 'key player' in establishing the Resting Membrane Potential due to its ability to diffuse out of the cell?

Potassium

Why is the inner surface of the plasma membrane negative relative to the outer surface in a resting cell?

The diffusion of Potassium out of the cell leaves behind negatively charged proteins.

Which organelle is known as the 'power plant' of the cell because it produces most of the cell's $ATP$?

Mitochondria.

What is the primary function of ribosomes?

They are the sites of protein synthesis.

The _____ Endoplasmic Reticulum is studded with ribosomes and is the site for synthesizing secreted proteins.

Rough

Which organelle functions in lipid metabolism, steroid synthesis, and drug detoxification?

Smooth Endoplasmic Reticulum.

What is the function of the Golgi apparatus?

It modifies, concentrates, and packages proteins and lipids received from the rough ER.

Which organelle contains acid hydrolases for digesting bacteria, viruses, and nonfunctional organelles?

Lysosomes.

What is the function of peroxisomes?

They use oxidase and catalase to detoxify harmful substances like free radicals and hydrogen peroxide.

What are the two major periods of the cell cycle?

Interphase and Cell Division (Mitotic Phase).

During which subphase of Interphase does DNA replication occur?

The $S$ (synthetic) phase.

What is the role of DNA polymerase during replication?

It attaches to the primer and adds nucleotides to form a new DNA strand.

Why is DNA replication called semiconservative?

Each new double-stranded DNA molecule consists of one old (template) strand and one new strand.

In mitosis, what happens during Prophase?

Chromatin condenses into chromosomes and the nuclear envelope breaks up.

In mitosis, what happens during Metaphase?

Chromosomes align precisely at the cell's equator (metaphase plate).

In mitosis, what happens during Anaphase?

Centromeres split and sister chromatids are pulled toward opposite poles.

What event defines the end of Telophase?

Two new nuclear membranes form around the separated chromatin sets.

_____ is the process of cytoplasmic division into two separate cells.

Cytokinesis

Which molecules serve as 'middlemen' or relays between extracellular first messengers and intracellular second messengers?

G proteins.

Which cell interaction molecules project from the membrane to anchor cells and direct cell migration?

Cell adhesion molecules (CAMs).

All stages of the cells?

Interphase, prophase, metaphase, telophase, anaphase

How many King Paimons can fit inside my bag

As much as I can fit