| What are the features of a prokaryote (and function) (6) | Nucleoid: region in cytoplasm where DNA is located, (DNA strand is circular = genosphere)
Plasmids: autonomous circular DNA molecules that can be transferred bw bacteria (horizontal gene transfre)
70S ribosomes: RNA + protein for translation
Cell wall: outer covering made of peptidoglycan to maintain shape and prevent bursting
Slime capsule: thick polysacch layer for protection against dessication (drying out) and phagocytosis
Flagella: long progections w/ motor protein for movement (flagellum)
Pili: hair like extensions to stick to surfaces / mediates bacterial conjugation |
| What are plasmids able to do? (4) | plasmids are autonomous molecules of circular DNA
they can be transferred bw bacteria by BACTERIAL CONJUGATION
mediated with a sex pilus
= exchange of genetic characteristics |
| How do pros asexually reproduce? | by binary fission
DNA is copied as a response to a replication signal
2 DNA loops attach to the membrane
membrane elongates and pinches off by cytokinesis
= 2 distinct cells |
| In what ways to pros and euks differ? (4) | DNA
pros: naked + circular DNA
euks: bound to protein + linear DNA
Organelles
pros: no membrane bound organelle + 70S ribosomes
euks: membrane bound organelles + 80S ribosomes
Reproduction
pros: binary fission + haploid
euks: mitosis and meiosis + diploid
Average size
pros: small (1-5 micrometers)
euks: large (10-100 micrometers) |
| What are eukaryotes? (4) | complex cells with a nucleus
compartmentalised cellular structure
membrane bound organelles
believed to have come from pros by endosymbiosis |
| What are organelles? | specialised sub structures in cells to do a specific function |
| What are the 4 types of eukaryotes? | protista: unicellular / multicellular without specialised tissue
fungi: chitin cell wall and are heterotrophs
plantae: cellulose cell wall and are autotrophs
Animalia: no cell wall and are heterotrophs |
| Draw an animal cell (9) | mitochondria
Smooth + rough ER
cytoplasm
cell membrane
ribosomes 80s
golgi apparatus
nucleus
nucleolus
Lysosome |
| Draw a plant cell (10) | golgi apparatus
smooth and rough ER
nucleus
ribosomes 80S
cell wall cellulose
chloroplast
vacuole
mitochondria
cell membrane
cytoplasm |
| Which organelles are present in both pro and euk? | ribosomes
cell membrane
cytoplasm |
| Which organelle is only present in animal cells? | lysosome |
| Which organelles are only present in plant cells? | chloroplasts
vacuole
cell wall (cellulose) |
| What is the structure and function of ribosomes? (3) | 2 subunits made of RNA and protein (80s in euk and 70s in pro)
site of polypeptide synthesis (translation) |
| What is the structure and function of the cell membrane? (2) | phospholipid bilayer embedded with proteins
semi-permeable + selective barrier around the cell |
| What is the structure and function of the nucleus? (3) | a double membrane structure with pores has an inner region (nucleolus)
stores genetic material (DNA) as chromatin and nucleolus is site of ribosome assembly |
| What is the structure and function of the endoplasmic reticulum? (3) | a membrnae network that can be smooth / rough (w ribsomes)
transports materials between organelles
smooth ER = lipids
rough ER = proteins |
| What is the structure and function of the golgi apparatus? | a group of vesicles and folded membranes near cell membrane
sorts and exports secretory products |
| What is the structure and function of a mitochondrion | double membrane structure = inner membrane highly folded
site for aerobic resp = ATP production |
| What is the structure and function of peroxisome? | membranous sac with catabolic enzymes
catalyses breakdown of toxic substances (H2O2) |
| What is the structure and function of centrosome? | microtubule organizing centre with paired centrioles in animal cells
radiating microtubules = spindle fibres which help with cell division (mitosis and meiosis) |
| What is the structure and function of chloroplasts? | double membrane structure with internal stacks of discs
site for photosynthesis = make organic mols that are stored in plastids |
| What is the structure and function of a vacuole? | fluid filled internal avity surrounded by tonoplast
maintains hydrostatic pressure |
| What is the structure and function of cell walls? | outer covering made of cellulose
provides support + mechanical strength and stops excess water uptake |
| What is the structure and function of lysosomes? | membranous sacs filled with hydrolytic enzymes
breaks down macromolecules |
| What are the two types of cells? | pros: have no nucleus ( archaea + bacteria)
euks have a nucleus (protista, fungi, plantae and animalia) |
| What are the two types of prokaryotes? | archaea = found in extreme environments (high temps = extremophiles)
Eubacteria = bacteria in pathogenic forms (E. Coli) |
