Biology - Unit 4: the life of the cell

cell

simplest collection of matter that is aliv

Light Microscope

Light passes through a specimen and then through magnifying lenses

Scanning Electron Microscope

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

Transmission Electron Microscopes

focus a beam of electrons through a specimen, providing a cross-section of the specimen

prokaryote

No membrane-enclosed nucleus
Circular DNA located in the nucleoid
No membrane-bound organelles
Includes bacteria and archaea
Size: 1 - 5 µm,
Age: 3.5 billion years old

Eukaryote

Have a membrane-enclosed nucleus
DNA stored in the nucleus
Has membrane bound-organelles
Includes protista, fungi, animals, and plants
Size: 10 - 100 µm,
age: 1.5 billion years old

Plant Cells

Has chloroplasts, cell walls, and huge vacuoles

Animal Cells

Have centrioles and lysosomes (some plants may have lysosomes)

Every Cell

has plasma membrane, cytosol, DNA, ribosomes, macromolecules, follow criteria for being alive.

Cell Size is limited by its surface area

exchange occurs at the surface and more surface area=more efficiency therefore more small cells means more efficiency

organelle

a specialized part of a cell; analogous to an organ in the human bod

nucleus

spherical storage of the DNA, manages cell functions, and contains mRNA which makes ribosomes.

Cytosol

gelatin-like fluid that lies inside the cell membrane that contains salts, minerals, and organic molecules and surrounds the organelles

ribosomes

two subunits of mRNA and a protein involved in making proteins.

Endoplasmic Reticulum

system of tubes that move things around the cell

Rough ER

ER but covered in Ribosomes that make and transport proteins.