Download Organelles: specialized subunits within a cell that have a specific

CH 5. The Eukaryote Cell
Cell membrane
Nucleus
Cytoplasm
Organelles: specialized subunits within a cell that have a specific
function. Individual organelles are usually separately enclosed
within their own lipid bilayers.
Nucleus: “nut”. First seen in 1858. Contains DNA. Information
center of the cell.
Nuclear envelope: a double layer with pores that let molecules
in and out
pores
Nucleus
nucleolus
Nuclear envelope: a double layer with pores
Nucleolus:
• small region in nucleus.
• Made up of RNA and proteins
• This is where ribosomes are made
• Chromatin - is a complex of DNA, RNA, and proteins
that forms chromosomes (packaged and folded DNA)
Organelles in the Cytoplasm
Mitochondria
• Convert chemical energy stored in foods into useful forms,
AKA respiration.
• Double membrane
• Have their own DNA, which is circular
• Thought to be ancient bacteria that coevolved into a
symbiotic (beneficial to both) relationship with cells
Organelles in the Cytoplasm
Chloroplast
• Trap sunlight energy and convert it into chemical energy
(photosynthesis)
• Similar structure as mitochondria
• Have their own DNA
Ribosomes:
• Where proteins are assembled
• Made of two RNA subunits and proteins
• Smallest of organelles (25 nm; 25 billionths of a meter)
• Dr. Shufran’s dissertation was on Ribosomal DNA
The tiny dots are ribosomes
Endoplasmic reticulum (ER):
• Complex network of sacs
• Transport materials through the inside of the cell
• Two types
• Smooth ER-smooth inside. Do not have particles or
granules. Store enzymes.
• Rough ER – rough inside. Dotted with MANY
ribosomes. Where proteins are made and modified,
exported and released.
Golgi apparatus (body): sac like
• Where proteins are modified, collected, packaged and
distributed.
Lysosomes: only in animal cells. Not in plant cells
• Form pockets around foreign materials and digest them
• Engulf microscopic particles (Endocytosis)
• Breakdown old organelles with enzymes
• Garbage cleaners of the cell
Vacuole: Sac-like structure that is used for storage.
• Water
• Salts
• Proteins
• Carbohydrates
Plastid: in plants. Many forms.
• Chloroplast
• Leukoplast – starches
• Chromoplast – pigments
Cytoskeleton: the cytoplasm is not simply like water or goo, as
once thought when I took high school biology.
It is made up of filaments that give it a framework.
• Microtubules
• Microfilaments
Sunfish, Leopomis spp.
Green sunfish
Bluegill