Anatomy- Chapter 3

cytology

the study of cellular structure and function

sex cells

germs cells or reproductive cells; sperm of males or the oocytes of females

somatic cells

body cells

plasma membrane

a phospholipid bilayer with embedded (integral) or attached (peripheral) proteins that separates the internal contents of the cell from its surrounding environment; separates the cytosol and the extracellular fluid

plasma membrane heads

hydrophilic (water loving); outsides

plasma membrane tails

hydrophobic (water fearing); inside

integral proteins

cannot be easily separated from the plasma membrane without damaging or destroying the membrane

peripheral proteins

bound to the inner or outer surface of the membrane and are easily separated from it

anchoring proteins

attach the plasma membrane to other structures and stabilize its position

recognition proteins

proteins that identify cells

receptor proteins

sensitive to the presence of specific extracellular molecules

carrier proteins

bind solutes and transport them across the plasma membrane

channels

forms a passageway completely though the plasma membrane; some are gated channels

glycocalyx

The external surface of a plasma membrane that is important for cell-to-cell communication

the components of the plasma membrane that allow it to perform its characteristic functions:

membrane lipids, membrane proteins, membrane carbohydrates

cytoplasm

general term for the material between the plasma membrane and the membrane that surrounds the nucleus

cytosol

intracellular fluid in which the organelles and inclusions are suspended

organelles

internal structures of cells that perform most of the tasks that keep a cell alive and functioning normally

inclusions

masses of insoluble materials

nonmembranous organelles

do not have a definite boundary; cytoskeleton, centrosome, ribosome, proteasomes

nonmembranous organelles with cellular extensions

microvilli, cilia, flagella

cytoskeleton

serves as the cell's skeleton; made of microfilaments, intermediate filaments, and microtubules

microfilaments

anchor the skeleton and interacting with other proteins to determine the consistency of the cytosol

intermediate filaments

strengthen the cell and help maintain its shape; stabilize the position of organelles

microtubules

A hollow rod composed of tubulin proteins that makes up part of the cytoskeleton in all eukaryotic cells and is found in cilia and flagella.

microvilli

increases the surface area of the cell; cover the surfaces of cells that are actively absorbing materials

centrosome

region of cytoplasm located next to the nucleus in a cell

centriole

aid the formation of the spindle apparatus needed for the movement of chromosomes

cilia

long, slender extensions of the plasma membrane

nonmotile primary cilium

acts as a signal sensor, detecting environmental stimuli and coordinating activities such as embryonic development and homeostasis at the tissue level

motile cilia

found on cells lining both the respiratory and reproductive tracts, and at various other locations in the body; they beat rhythmically to move fluids or secretions across the cell surface

flagellum

whip-like extension of the plasma membrane; only human cell with a flagellum is a sperm

ribosomes

responsible for protein synthesis; found scattered throughout the cytoplasm or fixed to the endoplasmic reticulum

proteasomes

remove and recycle damaged or denatured proteins

membranous organelles

endoplasmic reticulum, golgi apparatus, lysosomes, peroxisomes, mitochondria

endoplasmic reticulum

network of intracellular membranes continuous with the nuclear envelope

smooth endoplasmic reticulum

no fixed ribosomes; synthesis of lipids, fatty acids, and carbohydrates

rough endoplasmic reticulum

fixed ribosomes; produces proteins

golgi apparatus

Modifies, sorts, and packages proteins and lipids for storage or transport out of the cell

lysosomes

An organelle containing digestive enzymes; remove damaged organelles and destroy bacteria; do essential cleanup and recycling inside the cell

peroxisomes

absorb and break down fatty acids and other organic compounds; highest in metabolically active cells (liver cells)

mitochondria

produce energy in the form of ATP molecules

membrane flow

the continuous movement and exchange of membrane segments

nucleus

control center for cellular operations; stores all the information needed to direct the synthesis of different proteins in the human body; surrounded by a membranous nuclear envelope

Explain the difference between the cytoplasm and the cytosol

cytoplasm is the material between the plasma membrane and the nuclear membrane; cytosol is the fluid portion of the cytoplasm (aka intracellular fluid)

nuclear envelope

double membrane with two layers to separate the nucleus from the cytosol

nuclear pores

openings in the nuclear envelop to allow for chemical communication between the nucleus and the cytoplasm

nucleoplasm

fluid portion of the nucleus

nucleoli

transient nuclear organelles that synthesize ribosomal RNA

DNA

stores the instructions for protein synthesis

histones

protein molecules around which DNA is tightly coiled in chromatin

chromatin

loosely coiled DNA

genetic code

chemical 'language' the cell uses; a triplet code

gene

functional unit of heredity

describe the structure of the nucleus

cellular organelle that contains DNA, RNA, enzymes, and proteins; nuclear envelope; nuclear pores

cell division

Process by which a cell divides into two new daughter cells

apoptosis

genetically controlled death of cells

mitosis

duplication of the cell's genetic material and nuclear division into two identical sets

interphase

period of the cell cycle between cell divisions; performing all normal functions

cytokinesis

the physical process by which a single animal cell separates into two cells

stem cells

maintain cell populations through repeated cycles of cell division

dividing cells

require an unusually large amount of energy

tumor

mass or swelling produced by abnormal cell growth and division

cancer

any malignant growth or tumor caused by abnormal and uncontrolled cell division; do not use energy very efficiently

oncogenes

modified genes

mutagen

agents that cause a mutation

carcinogen

cancer-causing agents, which include many mutagens

metastasis

the spread of cancer to other areas

An illness characterized by mutations that disrupt normal control mechanisms and produce potentially malignant cells is termed

cancer

differentiation

development of specific cellular characteristics and functions that are different from the original cell; produces specialized cells with limited capabilities

fertilization

produces a single cell with all its genetic potential