Module 2- Cells and Tissues Flashcards
Smallest unit of life
Cell
Parts of a cell
plasma membrane, cytoplasm and nucleus
The very thin, semi-permeable boundary of the cell which separates two of the body’s major fluid compartments; the intracellular fluid within the cells and extracellular fluid outside the cells.
Plasma membrane
Substances diffuse directly through the lipid bilayer.
Simple diffusion
The transported substance either attaches to carrier proteins in the membrane and is ferried across or moves through water-filled channel proteins.
Facilitated diffusion
The passive transport (diffusion) of a solvent, such as water, through a selectively permeable membrane, from an area of lower concentration to higher concentration (or vice versa)
Osmosis
The ability of a solution to change the shape of cells by altering the cells’ internal water volume.
Tonicity
Cells retain their normal size and shape in isotonic solutions. They have same solute/water concentration as inside cells; no net movement of water.
Isotonic solutions
Cells lose water by osmosis and shrink in a hypertonic solution. They contain a higher concentration of nonpenetrating solutes than are present inside the cells. Eg. Sea water.
Hypertonic solutions
Cells take on water until they become bloated and burst in a hypotonic solution. They contain a lower concentration of nonpenetrating solutes than are present inside cells. Eg. Pure water.
Hypotonic solutions
Requires transport proteins that combine specifically and reversibly with the transported substances. Uses energy and moves substances across membrane against concentration gradient.
Active transport
The process where solutes are moved across cell membrane against electrochemical gradients using energy supplied directly by ATP.
Primary active
Transport is driven by energy stored in concentration gradients of ions created by primary active transport pumps.
Secondary active
‘Little organs’. Specialised cellular compartments or structures; each performing its own job to maintain the life of the cell.
Organelles
The internal environment of the cell, excluding the nucleus. It is a gel-like fluid, with a variety of organelles and inclusions within it.
Cytoplasm
The viscous, semitransparent fluid in which the other cytoplasmic elements are suspended.
Cytosol
Other bodies (chemical substances) that may appear in it temporarily and aren’t part of the permanent metabolic machinery of the cell.
Inclusions
The powerhouse of a cell, function in the production of most of the ATP (energy) supply. Enclosed in a double membrane.
Mitochondria
Small organelles composed of granules of RNA which have an important role in protein synthesis.
Ribosomes
System of interconnected tubes and parallel sacs which function in the transport and networking of molecules. 2 types; smooth & rough.
Endoplasmic Reticulum
Modifies substances produced in other parts of the cell and prepares/packages these products (protein) for secretion.
Golgi apparatus
Contains enzymes that breakdown toxic hydrogen peroxide molecules, a substance often generated in the degradation of large organic molecules.
Peroxisomes
Products of golgi apparatus and contain digestive enzymes to break down substances that need to be removed from the cell- particularly damaged organelles and pathogens.
Lysosomes
A system of organelle that work together mainly to 1) produce, degrade, store and export biological molecules, and 2) degrade potentially harmful substances.
Endomembrane system
An elaborate network of rods running through the cytosol and hundreds of accessory proteins that link these rods to other cell structures.
Cytoskeleton
whiplike, motile cellular extensions that occur on the exposed surfaces of certain cells. Its actions move substances in one direction across the cell surfaces
Cilia
projections formed by centrioles but longer. The only flagellated cell is a sperm which has one propulsive flagellum. It propels the cell itself
Flagella
tiny, finger-like extensions of the plasma membrane that project from an exposed cell surface. It increase the cell surface and and most often found in absorptive cells in the intestine and kidney
Microvilli
The cell’s control center.
Nucleus
The series of changes a cell goes through from the time it is formed until it reproduces.
Cell cycle
The period from cell formation to cell division. Cell grows and carries on usual activities.
Interphase
The process of nuclear division in which the chromosomes are distributed to two daughter nuclei. Prophase, metaphase, anaphase and telophase.
Mitosis
division of the
cytoplasm
Cytokinesis
A sheet of cells that covers a body surface or lines a cavity. Accomplishes many functions, including protection, absorption, filtration, excretion, secretion and sensory reception.
Epithelial tissue
The most abundant and widely distributed tissue in the body. There are four main classes; connective tissue proper (fat and fibrous tissue of ligaments), cartilage, bone and blood.
Connective tissue
Well-vascularised tissues that are responsible for most types of body movement. The cells are all tightly packed together and contain myofilaments.
Muscle Tissue
Packaged by connective tissue sheets into organs that are attached to the bones. They form the flesh of body and as they contract, they pull on bones or skin, causing body movements.
Skeletal muscle
Main tissue of the heart. Found only in the walls of the heart. Its contractions help propel blood through the blood vessels to all parts of the body.
Cardiac muscle
Found mainly in the walls of hollow organs other than the heart. It squeezes substances through these organs by alternating contracting and relaxing.
Smooth muscle
Its main component are the brain, spinal cord and nerves - which regulate and controls body functions by transmitting electrical signals. It contains two major cell types; neurons and supporting (glial) cells.
Nervous tissue
- Inflammation
- Organization restores the blood supply
- Regeneration and fibrosis effect permanent repair
Tissue repair
