Chapter 3A Human Physiology

Cytosol

________ is the fluid in a cell, but the cytoplasm is all of the cell contents.

Cholesterol

________ adds stability to the cell membrane.

plasma membrane

The ________ also acts as a double layer of phospholipids.

mitochondria

The ________ consumes oxygen and produces CO2, heat, and water.

plasma membrane

The ________ also senses chemical messengers and helps with cell signaling.

Organelles

membrane-bound structures that perform specific functions

Cytoplasm

everything inside cell membrane except the nucleus

Cytosol

fluid inside the cell membrane but outside of the organelles

Selective barrier

The function of the plasma membrane as it is surrounding whole cell, organelles, nucleus

Cellular Support

The plasma membrane function that anchors the cells to adjacent cells and the extracellular matrix (ECM)

Integral proteins

Proteins imbedded within the cell membrane

Transmembrane proteins

A subunit of integral proteins that form channels, transmitting cell signals from the extracellular fluids to the intracellular fluids

Peripheral Proteins

Proteins attached to inside or outside the cell membrane, but do not transverse the whole membrane; helps with enzyme activity and cell shape

Glycocalyx

This is a layer made of glycoproteins & carbohydrates used for cell recognition,

Cell Membrane Junctions

Physical connections between cells

Desmosomes

Membranes of adjacent cells linked by strong fibers in isolated spots

Tight Junctions

Membranes joined with no space between them, connections go all the way around the cell; restricts molecular diffusion between cells

Paracellular Pathways

A passive transport process that results in the transport of substances across an epithelium by passing through the intercellular spaces in between epithelial cells

Transcellular Pathways

A carrier-mediated, energy-dependent, active transport mechanism,

Gap Junctions

Protein channels that link the cytosol of adjacent cells; allows small molecules & ions to pass between cells & rapid cell communication

Cellular Organelles

Plasma membrane-bound structures that perform specific cellular functions

Nucleus

Largest cellular organelle, stores DNA

Nucleolus

Part of the nucleus, site of ribosomal RNA synthesis

Chromatin

Part of the nucleus, is the DNA

Nuclear evelope

Encases the nucleus and allows mRNA to pass into cytoplasm, also called pores

Ribosomes

An organelle that builds proteins by connecting amino acids; many of these in a cell

Free ribosomes

Ribosomes that release proteins into cytosol

Bound ribosomes

Ribosomes that are attached to the ER and release proteins into the ribosome

Endoplasmic Reticulum

A large continuous space encoled my membranes, has a rough and a smooth type

Rough ER

Contains ribosomes, involved in packaging of proteins

Smooth ER

Responsible for protein synthesis, Ca2+ handling

Golgi Apparatus

A series of flat membraned sacs that deal with protein modification & packages proteins into vesicles

Vesicle

A small sac that moves stuff into and out of a cell

Secretory vesicles

Vesicles that fuse with the cell membrane and release contents (proteins) to the extracellular fluid

Mitochondria

Produces the cells energy (ATP) and has inner & outer membranes and a matrix

Lysosomes

Contain acidic fluid and digestive enzymes used to break down bacteria, damaged

Peroxisomes

Contains enzymes that oxidize organic molecules like lipids and alcohol

Cytoskeleton

Generally made of proteins, this is NOT a membrane-closed organelle but helps maintain and change cell shrape