Histology and Tissue Types

Protoplasm

Different substances that make up the cell

Parts of the Protoplasm

1. Water

2. Electrolytes

3. Proteins

4. Lipids

5. Carbohydrates

Phospholipids

Hydrophilic heads and hydrophobic tails (mutual attraction = attachment)

Intracellular

Mainly in the form of long filaments

Extracellular

Fibrillar proteins: collagen & elastin fibers of connective tissues

Enzymes

Adhere to membranous structures to catalyze specific intracellular reactions

Triglycerides

Neutral fats; Fat stored represents body’s main storehouse of energy-giving nutrients that can later be used to provide energy

Carbohydrates

Major role in cell nutrition & good for generating energy

Determine the flexibility (permeable) of the membrane

Lipid Bilayer

Thick-double layered film of lipids continuously over the cell surface

Sphingolipids

Hydrophobic & hydrophilic groups

Present in nerve cells

Protect from harmful environmental factors, signal transmission & adhesion sites

Integral Proteins

Channels can move water & ions between intra/extracellular fluids = carrier proteins

Peripheral Proteins

Attached to integral proteins
Acts as enzymes or controllers of transport through pores

Pores

How protein molecules can penetrate through membranes

Glycocalyx

Loose carbohydrate “cell coat”:

*Negative electrical charge —> overall negative surface charge that repels other - charges

Cytosol

Jelly-like fluid that contains dissolved proteins, electrolytes, glucose, etc.

Endoplasmic Reticulum

Processes molecules made by the cell and transports them inside & out

Shares a metabolic function

Rough Endoplasmic Reticulum

Continuous with nuclear membrane and permits efficient exchange of info

Ribosomes

Attached to the outer surfaces of the ER

Composed of RNA & Proteins

Synthesizes new protein molecules

Smooth Endoplasmic Reticulum

NO ribosomes

Synthesizes lipid substances

Detoxifies drugs & poisons

Golgi Apparatus

Enclosed vesicles near one side of the nucleus

Function: Transportation of vesicles to other locations in the cell

*Secretory cells

Lysosomes

Prove intracellular digestion to:

damaged cellular structure, food particles, bacteria & viruses

Tay-Sachs Disease

Lysosome enzyme disorder

Accumulation of lipids —> nervous system damage, cognitive deficits, impaired motor skills

Peroxisomes

Form through self-rep or budding off of smooth ER

Catabolize long-chain fatty acids

Breakdown material through oxidases