C2 - Basic components

M2 - Foundations of biology

eukaryotic and prokaryotic cells - similarities

• both contain organelles

• cell membrane made of phospholipid bilayer

• bilayer responsible for passage of substances

prokaryotic cells - differences from eukaryotic

• single celled roganisms

• less complex, smaller

• binary fission makes new cells

• no membrane bound organelles

eukaryotic cells - differences from prokaryotic

• make up complex organisms

• larger and more complex

• create new cells by mitosis or meiosis

• contain membrane bound organelles

types of eukaryotic cells

• animal cell

• plant cell

• algae

• fungi

eukaryotic cells - fungi

• similar to plant cells

• no chloroplasts

• chitin cell walls

• can be multicellular

eukaryotic cells - algal cells

• identical organelles to plant cells

eukaryotic cells - plant cells

• contain all organelles in animal cells

• vacuoles - contains cell sap

• chloroplasts - site of photosynthesis

• cell wall - made of cellulose, contains plasmodesmata

eukaryotic cells - animal cells

• enclosed by cell membrane

• mitochondira

• ribosomes

• endoplasmic recticulum (sort and rough)

• nucleus

• lysosomes

• Golgi apparatus

nucleus - structure

• nuclear envelope

• nuclear pore

• nucleoplasm

• nucleolus

nucleus - nuclear envelope - structure + function

• double membrane structure - contains nuclear pores

• made of phospholipid bilayers

• pores control passage of ions, molecules and RNA (between the nucleoplasm and cytoplasm)

nucleus - nucleoplasm - structure

• semi-solid fluid inside the nucleus

• contains chromatin and the nucleus

• provides environment for reactions in the nucleus and maintains nucleus shape

nucleus - nucleolus - function

• likes within the nucleoplasm

• contains DNA with protein synthesis instructions

• controls actions of the cell

• in nucleolus = ribosome RNA joined with proteins to assemble ribosomal subunits

nucleus - nucleolus - structure

• largest sub structure within the nucleus

• made of protein, RNA, and DNA

• site of ribosome synthesis

• secondary role = immobilising proteins, forming signal recognition particles

mitochondria - structure

• oval shapes, double membrane

• contain ribosomes and their own DNA

• membrane is embedded with proteins

• inner membrane has cristae folds

• mitochondrial matrix

mitochondria - mitochondrial matrix - structure

• surround crustal folds inn the inner membrane

• contains enzymes for respiration

mitochondria - function

• makes ATP via aerobic respiration

• common in areas of high activity

chloroplasts - structure

• DNA, ribosomes and inner and outer membranes

• thylakoids

• grana

• lamellae

• stroma

chloroplasts - thylakoids - structure

• interconnected and stacked fluid filled sacs = thylakoids

• stack of thylakoids = granum (grana)

• what links grana = lamellae

chloroplasts - lamellae

• lamellae = flat thin parts of thylakoid membrane - links grana

• stroma = fluid around the grana, enclosed by inner membrane

chloroplasts - function

• photosynthesis occurs

• allows plants to make their own sugars

• in plant and algal cells

Golgi apparatus - structure

• serious of flattened membranous sacs

• vesicles

golgi apparatus - vesicles - structure

• vesicles = membrane bound, fluid filled vesicles located in the cytoplasm

• small, round

• seen in high density near edges of golgi sacs

• e.g. lysosomes

golgi apparatus - function

• transport vesicles from the ER fuse with the golgi

• vesicles empty proteins and lipids into the lumen of the golgi

• protein and lipids are sorted, packaged and tagged

golgi apparatus - vesicles - function

• store and transport modified proteins and lipids - transports to target cells

• lysosomes - contain lyzoenzymes - aid breakdown of proteins, polysaccharides, lipids, nuclei acids and old organelles

ribosomes - structure

• free floating in cytoplasm or attached to RER

• small organelles - made of protein subunits

• no membrane

ribosomes - function

• in charge of protein synthesis

• found in most cells

ER - structure

• a series of interconnected membranous sacs and tubules

• membrane - phospholipid bilayer embedded with proteins

RER - structure

• SER - no ribosomes

• RER - many ribosomes on surface

RER - function

processing and folding proteins

SER - function

• making and processing lipids

plasma membrane - structure

• phospholipids

• cholesterol

• glycoproteins

• glycolipids

• channel proteins

• integral membrane protein

• peripheral membrane protein

plasma membrane - phospholipids - structure

• phospholipids are amphipathetic = hydrophobic and hydrophilic

• hydrophilic - faces outwards

• hydrophobic - faces inward

• polar substances cant easily pass through

plasma membrane - function

• protects cells from their surrounding environemnt

• partially permeable - can mediate interactions between cells interior and its surroundings

• plays a role is cellualr processes e.g. cell signalling

• attach,emt point for some extracellular (e.g. cell wall) and intracellular structures (e.g. cytoskeleton)

cell wall - structure

• rigid covering that protects the cell

• in plant, fungal and algal cells

• fungal = chitin

• plant and algal = cellulose

cell wall - function

• provides structural support

• gives shape to the cell

centrioles - structure

• cylindrical shape

• parallel microtubules around a central cavity

• found as pairs at right angle to eachother

• only in isolation in basal regions of flagella/cilia (where they connect to the cell)

centrioles - function