Chapter 6

Cells

• All organisms are made of ___

• Smallest collection of matter that can be alive

• The structure is correlated to function

• All ___ are related by their descent from earlier ___

Cell Characteristics

All ___

• Surrounded by plasma membranes

• have cytosol

• contain chromosomes which have genes in the form of DNA

  • have ribsomes

cytosol

semi-fluid substance within the cellular membrane

ribosomes

tiny “organelles” that make proteins using instructions contained in genes

Prokaryotic Cell

• DNA in a nucleoid region, without a membrane separating it from the rest

• cell wall present in all

Eukaryotic Cell

• chromosomes in nucleus

• membrane enclosed organelles

• cell walls present in fungi, plants and some protists

• more complex

• membrance bound organellese present

Endosymbiosis Theory

• Mitochondria and chloroplasts were once free living bacteria

  • engulfed by ancestral eukaryote

Endosymbiont

• Cell that lives within other cells (host)

  • as a partnership

  • evolutionary advantage

    • one supplies energy

    • the other supplies raw materials and protection

What limits cell size?

Metabolic requirements set upper limit

Specialty Structures (importance of organelles)

specialized functions

Containers (importance of organelles)

• partition cells into compartments

• create different local environments

  • separate, pH, or concentration of materials

• distinct compatible functions

  • lysosome and its digestive enzymes

Membranes as sights for chemical reactions (importance of organelles)

• unique combo of lipids and proteins

• embedded enzymes and reaction centers

  • chloroplasts and mitochondria

Nucleus

• information central

• ___ makes ribosomes

Cells make protein

proteins control every function

Cells make energy

for daily life and to grow

Cells make more cells

to grow, repair and renew

Building Proteins require

• Organelles involved

  • nucleus

  • ribosomes

  • ER

  • golgi apparatus

  • vesicles

Order for building proteins

nucleus → ribosomes → ER → golgi apparatus → vesicles

Ribosome function

protein production

Ribosome structure

rRNA and protein

Rough ER Function

produce proteins for export out of cell

Smooth ER Function

• Membrane Production

• Many metabolic processes

  • synthesizes lipids

  • store calcium ions

  • hyrdolsis

Lysosome function

• little “stomach” of cells

  • digests macromolecules

• “clean up crew” of the cell

  • cleans up broken down organelles

Lysosome structure

vesicles of digestive enzymes

Cellular Digestion

Lysosomes fuse w/ food vacuoles

• polymers digested into monomers

• pass to cytosol to become nutrients of cell

When cells need to die

Lysosomes can be used to kill cells when they are supposed to be destroyed

apoptosis

• “auto destruct” process

• lysosome break open and kill cell