A2.2.6 - Eukaryote Cells Flashcards
Students should be familiar with features common to eukaryote cells: a plasma membrane enclosing a compartmentalized cytoplasm with 80S ribosomes; a nucleus with chromosomes made of DNA bound to histones, contained in a double membrane with pores; membrane-bound cytoplasmic organelles including mitochondria, endoplasmic reticulum, Golgi apparatus and a variety of vesicles or vacuoles including lysosomes; and a cytoskeleton of microtubules and microfilaments.
A little thing to help remember what eukaryotic cells are
What does the prefix eu & suffix kary mean?
Eu: well
Kary: nucleus
Typically has a well-defined nucleus
The eukaryote cell
What are some major characteristics of eukaryotes?
- Much larger & complex than PCs
- Has nucleus
- Some are multicellular
→ Meaning that some consists of more than one cell
There is huge diversity within the eukaryotes
The eukaryote cell
Compartmentalization in eukaryotic cells
- Eukaryotes contain membrane-bound organelles (i.e. mitochondria, chloroplasts) which are non-cellular structures. These structures enable compartmentalization.
→ Important for isolating different chemical reactions (helps prevent interference of reactions)
→ Higher concentrations of certain substances within organelles
→ Separates toxins & potentially damaging substances from the rest of the cell (i.e. hydrolytic enzymes stored in lysosomes away from the cell cytoplasm)
→ Control over conditions inside organelles (i.e. pH) to maintain optimal conditions for enzymes that function in those parts of the cell
The eukaryote cell
What are some examples of eukaryotes?
- Algae
- Protozoa
- Fungi
- Plants
- Animals
Typical cell components of Eukaryotes #1
What are the 3 main components of eukaryotes?
The 3 major characteristics of all cells
- Plasma membrane
→ Interior & exterior separation - Cytoplasm
→ Site of metabolic reactions
→ Suspends ions, organic molecules, organelles & ribosomes
→ Includes cytoskeleton (small fibres & rods) - Nucleus (DNA)
→ Has a double membrane containing pores (allows certain molecules to pass: i.e. glucose, RNA & ions)
→ Associated w/ histones & organized into chromosomes
→ Contains nucleolus; involved in the production of ribosomes
Typical cell components of Eukaryotes #2
About 80S ribosomes in eukaryotes
- For protein synthesis
- Larger than prokaryotic ribosomes (80S > 70S)
→ Higher mass & denser - Either free in the cytoplasm or attached to the surface of endoplasmic reticulum (ER)
- Always composed of a type of RNA or protein
- Usually ranges in diameter between 10~100µm
Ribosomes have 2 subunits
The 7 organelles (typical cell components)
The 2 ERs & Golgi Apparatus
- Smooth ER
→ Produces & stores lipids (i.e. steroids) - Rough ER
→ Ribosomes attached to exterior surface - Golgi Appartus
→ Processes & packages proteins to be released in golgi vesicles
The 7 organelles (typical cell components)
The Double Vs
- Vesicle
→ Small sac that transports & releases substances produced within the cell by fusing w/ cell membrane - Vacuole
→ Helps maintain osmotic balance of the cell
→ Stores substances
→ Has hydrolytic functions similar to lysosomes
The 7 organelles (typical cell components)
The final MC & L
- Mitochondria
→ Double-membrane-bound organelle that converts glucose into ATP during respiration - Cytoskeleton
→ System of protein fibres: microtubules & microfilaments
→ Aids cellular movements & anchors some organelles
→ Helps maintain structure & shape of cell - Lysosome
→ Contains as many as 40 enzymes
→ Fuses w/ old or damaged organelles to break them down
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