Chapter 3 - Cells: The Living Units

Selectively (semi) permeable

Determines which substances enter/exit the cell

Diffusion

The movement of molecules or ions from a high concentration to lower concentration

Osmosis

The diffusion of a solvent through a semi-permeable membrane (high concentration to low concentration)

Isotonic

Cells retain their normal size and shape; equal amount of water inside and outside of the cell

Hypertonic

Cells are shrunken and spiky; more water is outside of the cell than the inside (will undergo crenation)

Hypotonic

Cells are big and swollen; too much water is in the inside of the cell than the outside (will burst! aka lysis)

Facilitated diffusion

Certain molecules that can’t cross the semi-permeable membrane will do it with the help of carrier/channel proteins

Active transport

The cell provides the metabolic energy (usually ATP) needed to move substances against the concentration gradient

Endocytosis

Brings specific substances from the extracellular fluid into the cell

Exocytosis

Substances are ejected from the interior of the cell to the extracellular fluid

Phagocytosis

Engulfs large particles and combines with the lysosome to digest its contents

Pinocytosis

Drinks/slurps in extracellular fluids containing solutes into tiny vesicles

Plasma membrane

Semi-permeable membrane that separates 2 of the body’s major fluid compartments — intracellular and extracellular

Cytoplasm

The intracellular fluid that is packed with organelles

Nucleus

The “control center” organelle — controls the cellular activities

Mitochondria

The powerhouse of the cell; transforms food into glucose, and produces adenosine triphosphate (ATP)

Golgi complex

Packages and exports the proteins made by the endoplasmic reticulum (ER) to its destination

Peroxisomes

Very active in detoxing potential hazards in the body, also breaks down/synthesizes fatty acids

Smooth endoplasmic reticulum (SER)

Synthesizes & metabolizes lipids, and can also detoxify drugs

Rough endoplasmic reticulum (RER)

Imbedded with ribosomes and manufactures integral proteins

Flagella

Tail-like projection that propels the cell

Cilia

Tiny hairs that propel substances across the surface of the cell

Ribosome

Granules that make proteins — they can either be free or membrane bound

Microfilaments

Semi-flexible strands of actin protein that is involved in cell motility and shape

Lysosome

Power enzyme containing vesicles with super low pH digestive enzymes that clean, recycle, and rid of unwanted waste through exocytosis

Microvilli

Foldings or finger-like extensions of the plasma membrane; maximizes surface area for absorption

Mitosis

The division of the nucleus to replicate 2 identical daughter cells

Transcription

Transfers information from a DNA sequence to its complementary RNA sequence

Translation

The base sequence is translated into an amino acid sequence

What is labeled “F”?

Plasma membrane

What is labeled “D”?

Nucleus

What is labeled “G”?

Golgi complex

What is labeled “K”?

Lysosome

What is labeled “I”?

Mitochondria

What is labeled “J”?

Smooth endoplasmic reticulum (Smooth ER)

What is labeled “M”?

Rough Endoplasmic Reticulum (Rough ER)