Cell: The Unit of Life

Microbodies

Many membrane bound minute vesicles called microbodies that contain various enzymes, are present in both plant and animal cells.

Satellite

Non-staining secondary constrictions at a constant location

Nucleoplasm

the protoplasm that constitutes the nucleus of a cell

Perinuclear Space

Forms a barrier between the materials present inside the nucleus and that of the cytoplasm

Chromatin

the readily stainable substance of a cell nucleus consisting of DNA and RNA and various proteins

centrosome

small region of cytoplasm adjacent to the nucleus; contains the centrioles and serves to organize the microtubules

axoneme

Core of Flagellum

Cilia

Small structures which work like oars, causing the movement of either the cell or the surrounding fluid.

centrioles

cylindrical structures

cytoskeleton

a microscopic network of actin filaments and microtubules in the cytoplasm of many living cells that gives the cell shape and coherence

ribosome

an organelle in the cytoplasm of a living cell; they attach to mRNA and move down it one codon at a time and then stop until tRNA brings the required amino acid

thylakoids

organised flattened membranous sacs

chloroplast

plastid containing chlorophyll and other pigments; in plants that carry out photosynthesis

chromoplast

plastid containing pigments other than chlorophyll usually yellow or orange carotenoids

leucoplast

the colourless plastids of varied shapes and sizes with stored nutrient

plastid

any of various small particles in the cytoplasm of the cells of plants and some animals containing pigments or starch or oil or protein

vacuole

a tiny cavity filled with fluid in the cytoplasm of a cell

mitochondrion

an organelle containing enzymes responsible for producing energy

lysosome

an organelle found in the cytoplasm of most cells

golgi body

a netlike structure in the cytoplasm of animal cells

nucleus

the center of the head of a comet; consists of small solid particles of ice and frozen gas that vaporizes on approaching the sun to form the coma and tail

endoplasmic reticulum

network or reticulum of tiny tubular structures scattered in the cytoplasm

cell wall

a rigid layer of polysaccharides enclosing the membrane of plant and prokaryotic cells

cell membrane

a thin membrane enclosing the cytoplasm of a cell; proteins in the membrane control passage of ions in and out of the cell

active transport

transport of a substance across a cell membrane against the concentration gradient

passive transport

transport of a substance across a cell membrane by diffusion; expenditure of energy is not required

osmosis

diffusion of molecules through a semipermeable membrane from a place of higher concentration to a place of lower concentration until the concentration on both sides is equal

cytoplasm

the protoplasm of a cell excluding the nucleus; is full of proteins that control cell metabolism

protoplasm

the substance of a living cell

bacteria

single-celled or noncellular spherical or spiral or rod-shaped organisms lacking chlorophyll that reproduce by fission