A&P Chapter 3.2: Cell Biology

Cytoplasm composition

cytosol, cytoskeleton, cytoplasmic inclusions, and organelles

cytosol

the fluid portion of the cytoplasm surrounding the organelles

microtubules function

assist in intracellular transport, maintaining cell shape, and organizing cell division

Microfilaments function

Provide structural support, support microvilli, and aid in cellular contraction

Nuclear pores function

Regulate selective movement of substances in and out of the nucleus

Nucleolus site of assembly

ribosome synthesis and assembly

free ribosomes function

synthesize proteins intended for use inside the cytosol

bound ribosomes function

synthesize integral membrane proteins and proteins destined for secretion

rough endoplasmic reticulum

membranous network studded with ribosomes involved in processing proteins for export or membranes

smooth endoplasmic reticulum

synthesizes lipids, phospholipids, and steroids, and detoxifies chemicals; abundant in liver cells

golgi apparatus function

modifies, sorts, and packages proteins received from the rough ER into transport vesicles

lysosome

organelle containing hydrolytic enzymes used for intracellular digestion and autophagy

autophagy

process by which a cell intentionally digests its own damaged or unneeded organelles

peroxisome function

contains oxidative enzymes to break down fatty acids and amino acids

transcription site and product

occurs in the nucleus; produces an mRNA copy of a DNA sequence

translation site and mechanism

occurs at ribosomes; tRNA brings amino acids corresponding to mRNA codons to synthesize proteins

interphase components

G1 (growth), S (DNA replication), and G2 (preparation for cell division)

prophase key events

chromatin condenses into visible chromosomes, nuclear envelope breaks down, and spindle forms

metaphase key event

chromosomes align along the center of the cell (metaphase plate)

anaphase key event

spindle fibers separate sister chromatids and pull them to opposite poles of the cell

telophase key events

chromosomes decondense and nuclear envelopes reform around two new sets of chromosomes

synapsis and crossing over

Occurs in Meiosis I; homologous chromosomes pair (synapsis) and exchange DNA segments (crossing over)

Mitosis outcomes vs Meiosis outcome

Mitosis produces 2 identical diploid daughter cells; Meiosis produces 4 genetically varied haploid gametes

apoptosis

programmed cell death used to remove unwanted, damaged, or dangerous cell

Benign vs Malignant tumors

Benign tumors are localized and non-invasive; malignant tumors invade surrounding tissues and metastasize