Selective barrier thath allows suffiecient passage of oxygen, nutrients, and waste to service the volume of the cell

Double layer of phospholipds 

[image]

Contains most of the cell's genes 

Enclosed in the nuclear envelope, a double membrane, each consists of a lipid bilayer[image]

Pores regulate entry and exit of molecules from nucleus 

Shape is maintained by nucleur lamina which is composed of protein 

In the nucleus, DNA and proteins form genetic material called chromatin 

Chromatin condense to form discrete chromosomes 

Nucleoulus is located within the nucleus and is the site of ibosomal RNA (rRNA) synthesis 

Particles made of ribosomal RNA and protein 

Carry out protein synthesis in two locations:

In the cytosol (free ribosomes)

On the outside of the endoplasmic reticulum or the nuclear envelope (bound ribosomes)

Regulates protein traffic and performs metabolic functions in the cell 

Components:

Nuclear Envelope, endoplasmic reticulum, golgi apparatus, lysososmes, vacuoles, plasma membrane 

Thes components are either continuous or connected via transfer by vesicles

Endoplasmic Reticulum 

Biosynthetic factory 

Has assloads of membrane

Continuos with the nuclear envelope 

Two distinct regions:
Smooth ER - Lacks ribosomes

Rough ER - ribosomes stud the surface 

 [image]

(Endoplasmic Reticulum)

Functions: 

Synthesizes lipids 

Metabolizes carbohydrates 

Detoxifies poison 

Stores calcium 

(Endoplasmic Reticulum) 

Has bound ribosomes which secrete glycoproteins (Proteins covalently bonded to carbohydrates)

Distributes transport vesicles, proteins surrounded by membranes 

Is the membrane factory of the cell

Consists of flattened membranous sacs called cisternae 

Functions: 

Modifies products of the ER 

Manufactures certain macromolecules 

Sorts and packages materials into transport vesicles [image]

Lysosome 

A membraonous sac of hydrolytic enzymes that can digest macromolecules 

Lysosomal enzymes can hydrolyze proteins, fats, polysaccharides, and nucleic acids 

Some cells can engulf another cell by phagocytosis, which forms a food vacuole. A lysosome fuses with the food vacuole and digests the molecules 

Can also use enzymes to recycle the cell's own organelles and macromolecules, a process known as autophagy 

The sites of cellular respiration, a metabolic process that generates ATP 

Has a double membrane 

Have proteins made by free ribosomes 

Contain their own DNA 

In Nearly all eukaryotic cells 

Have a smooth outer membrane and an inner membrane folded into cristae 

Inner membrane creates two compartments: Intermembrane space and mitochondrial matrix

Cristae present a large surface area for ATP synthesis via enzymes [image]

Chloroplast 

Found in plants and algae and is the site of photosynthesis 

Member of the organelle family known as plastids

Contains the green pigment chloroyphyll, as well as enzymes and other molecules that function in photosynthesis  

Not part of endomembrane system 

Double membrane

Have proteins made by free ribosomes 

Contain their own DNA 

Structure:

Thylakoids, membranous sacs, stacked to form a granum. Stroma is the internal fluid [image]

Peroxisomes 

Specilized metabolic compartments bounded by a single membrane 

Produce hydrogen peroxide and convert it to water 

Oxygen is used to break down different types of molecules 

Cytoskeleton

A network of fibers extending throughout the cytoplasm 

Organizes the cell's structures and activites, anchors many organells 

Helps support the cell and maintain its shape

Interacts with motor proteins to producte motility. Vessicles can travel along monorail type structures provided by the cytoskeleton 

Composed of three types of molecular structures:

Mictrotubules, microfilaments, intermediate filaments

[image]

Thickest of the components used by the cytoskeleton 

Structure: Hollow tubes 

Protein Subunit: Tubulin

Functions: Shape integrity of the cell, cell motility, chromosome movement in cell division, organelle movement [image]

Thinnest component of the cytoskeleton 

Structure: Two intertwined strands of actin 

Protein Subunit: Actin 

Main Functions: Cell shape maintenance, changes in cell shape, muscle conractions, cytoplasmic streaming, cell motility, cell division 

Middle sized fiber used in the cytoskeleton 

Structure: Bibrous proteins supercoiled into thicker cables

Protein Subunits: One of the several different proteins of the keratin family 

Main functions:Maintenance of cell shape, anchorage of nucleus and certain other organelles, formation of nucleu lamina 

Locomotor appendages on some cells

Differ in their beating patterns 

Share a common ultrastructure:

A core of Mictrotubules sheathed by the plasma membrane 

A basal body that anchors the cilium or flagella 

A motor protein called dyenin, which drives the bending movements of cilium or flagellim [image]

Cytoplasmic Streaming 

A circular flow of cytoplasm within cells

The streaming speeds distribution of materials within the cell

In plant cells, actin-myosin interactions and sol-gel transformations drive cytoplasmic streaming 

An extracellular structure that distinguishes plant cells from animal cells

Found in prokaryotes, fungi, and some protists

Protects the plant cell, maintains its shape, and prevents excessive uptake of water 

Made of cellulose fibers embedded in other plysaccharides and protein 

Have Multiple Layers: 

Primary Cell Wall - Relatively thin and flexible 

Middle Lamella: Thin layers between primary walls of adjacent cells

Secondary Cell Wall (In some cells): added betweem the plasma mambrane and the primary cell wall 

Plasmodesmata 

Surrounds and is inbetween animal cells 

Made up of glycoproteins such as collagen, proteoglycans, and fibronectin

EXM proteins bind to receptor proteins in the plasma membrane called integrins

Functions:

Support, adhesion, movement, regulation

[image]

Help facilitate direct physical contact in neighboring cells 

Severl Types:

Plasmodesmata

Tight Junctions

Desmosomes 

Gap Junctions 

Desosomes 

An anchoring junction

Fastens cells together into strong sheets 

Gap Junctions 

A communicating junction

Provides cytoplasmic channels between adjacent cells