ANATOMY 1 Lecture Notes - Lecture 4: East Los Angeles College, Protoplasm, Nucleoplasm
Document Summary
Some cells anucleated (no nucleus), like mature rbc"s. Some cells are multinucleated (multiple nuclei), like skeletal & muscle cells. Nucleoplasm: protoplasm that is made up mostly of water, a mixture of various molecules, and dissolved ions. It is completely enclosed within the nuclear membrane or nuclear envelope. It is a highly gelatinous, sticky liquid that supports the chromosomes and nucleoli. Chromatin: dna + protein (histones); non-dividing cell; the substance distributed in the nucleus of a cell that condenses to form chromosomes during cell division. It consists mainly of dna and proteins (histones) Extended chromatin: dna helix opened up, not wound. Chromosome: colorful body ; super coiled; made up of 2 chromatids; Nuclear envelope contains 4 layers of phospholipids because each membrane is composed of 2 phospholipid layers. Factory that synthesize the 2 subunits of ribosomes. Leave nucleus through pores, 2 sub-particles combine in cytoplasm. Not all somatic cells divide: neurons/nerve cells. We grow a new epidermis every ~30 days.
