cell structures. cell structures barriers… cell wall plants & prok. (not animals) plants...
TRANSCRIPT
Cell Structures
Cell Structures
Barriers… Cell Wall
Plants & prok. (not animals)Structural (plant support) & protective
roleCellulose in plantsFreely permeable
Barriers…Cell Membrane (plasma membrane)
In ALL cells
Support/protection Regulates movement in/out of:
WaterNutrientsWaste products
Cell Membrane...
Barriers…Nuclear Envelope (nuclear membrane)
Surrounds nucleus
Thousands of poresMaterial move in/out, incl. RNA
Nuclear envelope
Fluids…Cytoplasm (cytosol)
Bet. cell mem. and nuclear env., site of most chemical activity
NucleoplasmSemi-fluid medium of nucleus
ProtoplasmTerm used for all substances inside cell
The Control Center
The Nucleus
The Nucleus…Controls most cell processes
Contains ChromatinDNA bound to proteins
During cell division, condenses to Chromosomes…
Has a NucleolusSmall, dense region
Assembly of Ribosomes
Nuclear Envelope (or membrane)
Little Organsassist the cell in conducting
reproductive, respiratory, and structural needs
Organelles of the
cytoplasm
Cytoskeleton… Protein filaments
Maintains cell shape
Involved in cell movement
Cytoskeleton
Mitochondrion…Uses energy from food
Makes high-energy compounds (ATP) needed for Rx elsewhere.
Ribosomes…Small, made of RNA (is an RNA molecule)
Assembly of proteins
Free in cytoplasm or attached to Rough ER
Endoplasmic Reticulum…
Large, assists with other organelle movement
Two types: Rough ER (RER)
○ Ribosomes stud surface○ Aids in synthesis and modif. of proteins○ Found wrapped around nucleus, extending into
cytosol Smooth ER (SER)
○ No ribosomes, attached to distal RER○ Synthesis of lipids, phospholipids, steroids (Plentiful in testes, ovaries, skin oil glands)
Golgi Apparatus…Receives proteins from rough ER
Enzymes attach carbs and lipids to the proteins
Can store proteins until needed
Proteins then sent to final destination(within cell or outside – exocytosis)
PACKAGING and SHIPPING
Golgi Apparatus
Vacuoles…Saclike structure
Stores water, salts, proteins, carbs
Can be large in plant cellsHelps in plant support by keeping turgor pressure high
Vacuoles
Vacuoles
Korotnovella, an amoeba. Inside this cell we can see a nucleus near the center with a rather angular dark nucleolus, various food vacuoles, and a clear round contractile vacuole at about 10 o'clock.
Lysosomes…Filled with enzymes (like H2O2)
Breaks down lipids, carbs, and proteins from food
old organelles
debris and harmful invaders
Plastid 1: Chloroplasts…
In plants, not animals or fungi
Uses sunlight to make energy rich food mol. thru photosynthesis (psyn)
Chloroplasts…
Chloroplast
Plastid 2: Leucoplast
Sometimes called amyloplast; stores starch (amylose)
Plastid 3: Chromoplast
Stores pigments in plants
CentriolesCylindrical; group of microtubules
In animal cells, used in cell division
As “basal bodies,” form cilia and flagella
Cell membrane - Structure
A phospholipid contains-
one head; negatively charged phosphate group that is hydrophilic (water-loving)
two tails of fatty acid chains that are hydrophobic (water fearing)
The Cell Membrane
Made of a phospholipid bilayer
regulates what passes in/out
Supports and protects
Selectively permeable – only certain things pass through.
5 nm thick
Cell membrane features
The fluid mosaic modelfluid in nature cell mobilityWithin mem. are various proteins for:
enzyme activity,cell attachment,communicating with other cells, Trans. of substances in and out
