AP BIO: unit 6 VOCAB

Light Microscope (LM)

Used to visualize cells

Electron Microscopes (EMs)

Used to study subcellular structures

Scanning electron microscopes (SEMs)

Focuses a beam of electrons onto the surface of a specimen, providing images that look 3-D

Transmission electron microscopes (TEMs)

Focuses a beam of electrons through a specimen, used to study the INTERNAL structure of cells

Cell fractionation

Takes cells apart and separates the major organelles from one another, helps determine the function of organelles

Basic cell types

Eukaryotic (plants, animals, fungi) & prokaryotic (bacteria) cells

Basic features of all cells

• Plasma membrane

• Semifluid substance called cytosol

• Chromosomes (carry genes)

• Ribosomes (make proteins)

Eukaryotic cells have…

• DNA bound by nuclear envelope

• Membrane-bound organelles

• Cytoplasm

• Mitochondria

Prokaryotic cells have…

• No mitochondria

Cell suface area to volume ratio

As a cell increases in size, its volume grows proportionately more than its surface area, limits cell size

Nucleus

Contains most of the cell’s genes and is usually the most conspicuous organelle

Nuclear envelope

Encloses the nucleus, separating it from the cytoplasm

Chromosomes

Single units of DNA molecule

Chromatin

DNA and protein of chromosomes bind together

Nucleolus

Located within the nucleus and is the site of ribosomal RNA (rRNA) synthesis

Ribosomes

Complexes made of ribosomal RNA and protein, carry out protein synthesis

Endomembrane system

Regulates protein traffic and performs metabolic functions in the cell, consists of

• Nuclear envelope

• Endoplasmic reticulum

• Golgi apparatus

• Lysosomes

• Vacuoles

• Plasma membrane

Smooth ER

• Synthesizes lipids

• Metabolizes carbohydrates

• Detoxifies drugs and poisons

• Stores calcium ions

Rough ER

• Has bound ribosomes, which secrete glycoproteins (proteins covalently bonded to carbohydrates)

• Distributes transport vesicles, secretory proteins surrounded by membranes