65 terms

Chapter 3: Cells and Tissues

Parts of Chapter 3: Cells and Tissues. This set includes: Anatomy of the Cell, Cell Extensions, Cell Diversity, Cell Physiology, Life Cycle of Cell
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Cells
The building blocks of all living things
Tissues
Groups of cells that are similar in structure and function
Nucleus
Control center of cell, contains DNA, necessary for cell reproduction.
Nuclear Envelope
Encloses the jelly-like fluid nucleoplasm in which other nuclear elements are suspended
Nucleoli
One or more may be present in the nucleus, site of ribosome assembly
Chromatin
When a cell is not dividing, its DNA is combined with protein and forms a loose network of bumpy threads called _________.
Chromosomes
When a cell is dividing to form two daughter cells, the chromatin threads coil and condense to form dense, rod-like bodies called ___________.
Plasma Membrane
A fragile, transparent barrier that contains the cell contents and separates them from the surrounding environment.
Hydrophobic
The __________ makeup of the membrane interior makes the plasma membrane relatively impermeable to most water-soluble molecules.
Tight Junctions
Impermeable, bind cells together into leak-proof sheets
Desmosomes
Anchoring junctions that prevent cells from being pulled apart
Gap junctions
Allow communication between cells
Cytoplasm
The cellular material outside the nucleus, inside the plasma membrane. The "factory area" of the cell.
Cytosol
Semi-transparent fluid that suspends other elements
Inclusions
Chemical substances such as stored nutrients or cell products. May or may not be present depending on cell type
Organelles
Metabolic machinery of the cell
Mitochondria
The "powerhouse" organelles that convert the chemical energy stored in food into compounds that are more convenient for the cell to use
Ribosomes
Site of protein synthesis found in two locations: free in cytoplasm, as part of rough ER
ER: Endoplasmic Reticulum
Fluid filled tubules for carrying substances
Golgi Apparatus
Modifies and packages proteins ("Traffic Director"), produces different types of packages
Lysosomes
Contain enzymes that digest worn out or non-usable materials within the cell
Peroxisomes
Membranous sacs of oxidase enzymes that detoxify harmful substances such as alcohol and formaldehyde and break down free radicals. Replicate by pinching in half
Cytoskeleton
Network of protein structures that extend throughout the cytoplasm
Microfilaments
Fine, threadlike proteins found in the cell's cytoskeleton
Intermediate filaments
Rope-like strands of protein that help to form desmosomes and resist pulling forces on the cell, located in the cell's cytoskeleton
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.
Centrioles
Rod shaped bodies made of a pinwheel array of fine microtubules, lie at right-angles to each other and direct the formation of mitotic spindle during cell division
Cilia
Move materials across the cell surface (located in the respiratory system to move mucus)
Cell Extensions
Cilia, Flagella and Microvilli
Microvilli
Finger-like projections of the plasma membrane that project from an exposed cell surface and increase surface area for absorption.
Cells that connect body parts
Fibroblast (has abundant rough ER and a large golgi to make and secrete the protein building blocks of these fibers), and Erythrocyte (red blood cell): carries oxygen in bloodstream.
Cells that cover and line body organs
Epithelial cells (shape allows packing together)
Cells that move organs and body parts
Skeletal muscle and Smooth muscle cells - These cells are elongated and filled with abundant contractile filaments, so they can shorten forcefully and move the bones or change the size of internal organs.
Cells that store nutrients
Fat cells - Produced by large lipid droplet in its cytoplasm.
Cells that fight disease
Macrophages (phagocytic cells): extends long pseudopods to crawl through tissue to reach infection sites.
Cells that gathers information and control body functions
Nerve cells (neuron) - This cell has long processes for receiving messages and transmitting them to other structures in the body. The processes are covered with an extensive plasma membrane, and a plentiful rough ER is present to synthesize membrane components.
Membrane Transport
Movement of substances into and out of a cell
Passive Transport
Movement of molecules through the plasma membrane according to the dictates of osmosis, diffusion or filtration.
Diffusion
Particles distribute themselves evenly and movement is from high concentration to low or down concentration gradient.
Simple Diffusion
Unassisted, solutes are lipid-soluble materials or small enough to pass through membrane pores.
Osmosis
A type of passive transport that occurs when water diffuses through a cell membrane. Highly polar water molecules easily cross the plasma membrane through aquaporins.
Facilitated Diffusion
Transports lipid-insoluble and large substances through a cell membrane along a concentration gradient with the aid of carrier proteins.
Filtration
Solute-containing fluid is pushed from a high-pressure area to a lower pressure area through a membrane by fluid, or hydrostatic pressure.
Active Transport (ATP)
Substances are transported that are unable to pass by diffusion because they are too large, not be able to dissolve in the fat core of the membrane, or have to move against a concentration gradient.
Solute Pumps
Amino acids, some sugars and ions are transported by protein carriers called _________.
Vesicular Transport
Involves the movement of materials within small membranous sacks;
always active; two major categories: endocytosis & exocytosis
Exocytosis
Active transport process by which a substance is released from the cell through a vesicle that transports the substance to the cell surface and then fuses with the membrane to let the substance out.
Endocytosis
Active transport process where a cell engulfs materials with a portion of the cell's plasma membrane and releases the contents inside of the cell.
Phagocytosis
Cellular "eating"; a type of endocytosis whereby a cell engulfs macromolecules, other cells, or particles into its cytoplasm.
Pinocytosis
A type of endocytosis in which the cell ingests extracellular fluid and its dissolved solutes.
Solution
Homogeneous mixture of two or more components
Solvent
Dissolving medium, typically water in the body
Solutes
Components in smaller quantities within a solution
Interstitial fluid
Fluid that fills the spaces between most of the cells of the body and that provides a substantial portion of the liquid environment of the body.
Intracellular fluid
Fluid within cell membrane; aka cytoplasm + nucleoplasm
Selective Permeability
Plasma membrane allows some materials to pass while excluding others; influences movement into and out of the cell
Interphase
The period in the cell cycle when the cell is not dividing. Cellular metabolic activity is high, chromosomes and organelles are duplicated, and cell size may increase. Accounts for 90% of the cell cycle.
Cell Division
Cell replicates to produce more cells for growth and repair process
DNA Replication
Genetic material is duplicated and readies a cell for division into two cells, occurs toward the end of the interphase.
Mitosis
In eukaryotic cells, a process of cell division that forms two new nuclei, each of which has the same number of chromosomes
Prophase
First part of cell division in which centrioles migrate to the poles to direct assembly of mitotic spindle fibers, DNA appears as double-stranded chromosomes, and the nuclear envelope breaks down and disappears
Metaphase
Second stage of mitosis, in which chromosomes are aligned in the center of the cell.
Anaphase
Third phase of mitosis, during which the chromosome pairs separate and move toward opposite poles, cell begins to elongate.
Telophase
Final stage of mitosis during which chromosomes uncoil to become chromatin, nuclear envelope reforms around each new set of chromosomes, spindles break down and disappear.
Cytokinesis
The final stage of the cell cycle. Division of the cytoplasm begins when mitosis is near completion. A cleavage furrow forms to pinch the cells into two parts, results in the formation of two daughter cells.