4.1-4.3 Cells

Cell theory

All organisms are composed of cells and the basic unit of structure and function

Cell size

Range in size of 1 millimeter(mm) down to 1 micrometer in diameter. They need a large surface for plasma membrane

The surface to area to volume requires?

That cells be small

Large cells surface area

Relates to volume decreases (decreases transport efficiency

Small cells

Larger surface area to volume ratio is advantageous for exchanging molecules

Nuclear envelope

Double membrane with nuclear pores that enclose the nucleus

Chromatin

Diffuse threads containing DNA and protein

Nucleolus

Region that produces subunits of ribosomes

Endoplasmic reticulum

Protein and lipid metabolism

Rough ER

Studded with ribosomes that synthesize proteins

Smooth ER

Lacks ribosomes synthesize lipid molecules

Peroxisome

Vesicle that is involved in fatty acid metabolism

Polyribosome

String of ribosomes simultaneously synthesizing same protein

Mitochondrian

Carries out cellular respiration

Cytoplasm

Semifluid matrix outside the nucleus that contains organelles

Lysosome ❌🌱

Vesicle that digests macromolecules and even cell parts

Vesicles

Small membrane bound sac that stores and transports subunits

Centrolies ❌🌱

Short cylinders of microtubules

Actin filaments

Protein fibers that help cell division and its shape

Intermediate filaments

Protein fibers that provide stability or shape

Microtubules

Protein cylinders that move organelles

Cytoskeleton

Maintains cell shape and assists moving cell parts

Plasma membrane

Outer surface that regulates entrance and exit of molecules

Golgi apparatus

Process, packages and secrets modified protein (repairs)

Nucleus

Command center of the cell

Central vacuole ❌🦧

Large fluid filled sac that stores metabolites and helps maintain larger pressure

Chloroplast ❌🦧

Carries out photosynthesis,producing sugars

Cell wall ❌🦧

Outer surface that shapes supports and protects the cell

Prokaryotes

Lack a membrane bound nucleus

Structure of prokaryotes

Spherical coccus

Rod shaped bacillus

Spiral spirillum

Gkycocalyx

Layer of polysaccharides on the outside of the cell wall cytoplasm and external structure

Plasmids

Are small accessory extra chromosomal rings of DNA

Ribosomes

Are tiny structures in the cytoplasm that synthesize protiens

Flagella

Provide mobility

Frimbriae

Small bristle like fibers that sprout from cell surface

Conducation pili

Rigid tubular structure used to pass DNA from cell to cell ( singular pili )

Eukaryotic cells

Membrane bound that houses DNa and plasma membrane

Eukaryotic cells are what compared to prokaryotic

Larger

Organelles are

Organs of the cell

Endosymbiotic

Energy organelles originated when larger cells engulfed smaller prokaryotic cells

Orgin of eukaryotic cells

First cells were prokaryotic. Biochemical data shows eukaryotes were more related to archaea than bacteria, the nucleus evolved by invagination.

Ivagination

Explains origins of endoplasmic reticulum and Golgi apparatus

Endomembrane system

Organelles that communicate with one another via membrane channels and small vesicles

Energy related organelles

Mitochondria and chloroplasts ( independent)

Structure of a eukaryotic cell

Plant and animal cell diagrams are generalized for study purposes. Specialized cells may have more or fewer copies of organelles depending on their function

Structure of eukaryotic cell prt 2

Production of molecules takes place in organelles by enzymes. Products are transported by vesicles protein fibers

Protien fibers

Railroad tracks. Plants cells fungi and many protists have cell walls. Plant cell walls contain cellulose a structural polysaccharide.