unit 1

definition of a cell

cell our

membrane enclosed units

in eukaryotic cells the membrane is what

semipermeable

what types of transport occur across a semipermeable

• free transport - diffusion

• active transport - ATP is consumed

give an example of a molecule that passes freely across the membrane

H20

CO2

what are the 2 types of active transport

• primary

• secondary

give me an example of transporters used in active transport

SGLT + GLUT (glucose transporters)

what is inside the cells (its internal environment)

aqueous solution

what is the name of the aqueous solution that is our cells internal environment

cytoplasm

in the case of eukaryotes the cytoplasm is composed of

water and many organelles

why are chemical concentrations important in cells

they affect many cellular processes such as metabolism and signalling

apart of water and organelles there are chemicals / biomolecules in the cytoplasm what are they

enzymes (for glycolysis)

proteins

where is located glycolysis

cytoplasm

what are the proteins in the cytoplasm classified as

the cytoskeleton

what does growth and division refer to in cells

the cell cycle

the cell cycle

done

what are the main stages of the cell cycle

G0

G1 - gap 1

S - synthesis

G2 - gap 2

M - mitosis

which stages of the cell cycle do we increase the size of the cell

G1

S

G2

where does division happen in the cell cycle

mitosis

what happens in the G0 stage

division is stopped

some cells are always in the G0 stage , example of cells in here

neurones

who first observed and named cells

Robert Hooke

what organism did Hooke observe to describe cells

cork sheets - plant cells

what was Hooke’s main contribution to cell biology

first to use the term cell after observing microscopic structure

who built a simple microscope to observe bacteria and red blood cells

Anton van Leeuwenhoek

what cells did Leeuwenhoek observe

microorganisms - bacteria

animal cells - red blood cells

Leeuwenhoek VS Hooke

who worked with plant cells

Hooke

Leeuwenhoek VS Hooke

who worked with animal cells

Leeuwenhoek

which scientists are considered the founders of cell theory

• Schleiden

• Schwann

• Virchow

what did Schleiden study

plant cells

what did Schwann study

animal cells

what did Schwann and Scheilen discover

many cells working together forms tissues

what did S + S conclude

cells are the universal building blocks of all living tissues and individuals are made of of cells

Virchow introduced the idea of what

“all cells come from other cells”

mitosis

difference between mitosis and meosis ?

done

what is cellular theory

cells are the fundamental units of life

state the 3 postulates of cellular theory

• all organisms are made up of cells

• cells are the basic structural unit (form tissues)

• cells arise from pre-existing cells (mitosis)

properties of a living system

done

what is the first cell on earth

prokaryotic cell

do prokaryotic cells have membrane-bound DNA

no

what does it mean by supposed evolutionary transition of eukaryotes

prokaryotes evolved into eukaryotes

what is the key difference between eukaryotes and prokaryotes ( mainly DNA)

• Eukaryotes - DNA is contained within a nuclear membrane/envelope

• prokaryotes - DNA is free floating in the cytoplasm in a region called the nucleoid

(and size)

in eukaryotes do some organelles contain DNA

yes

which 2 organelles inside eukaryotic cells contain DNA

• mitochondria (mitochondrial DNA)

• chloroplast

what is the theory that explains how prokaryotes transitioned into eukaryotes

Endosymbiosis

who is the founder of Endosymbiosis theory

Lynn Margulis

there are 2 separate processes for endosymbiosis why?

prokaryotic cell → eukaryotic animal cell

prokaryotic cell → eukaryotic plant cell

4 steps to get from prokaryotic cell to eukaryotic animal cell

1. prokaryotic cell

2. phagocytosis of Aerobic microorganism

3. aerobic microorganism is transformed into mitochondrion (by evolution)

4. eukaryotic animal cell

in the creation of an animal cell - what supports endosymbiosis theory

• the size of the mitochondrion and aerobic microorganism are the same

• free DNA inside both mitochondrion and aerobic microorganism

animal - read

done

4 steps for the formation of a plant cell

1. prokaryotic cell

2. phagocytosis of photosynthetic bacterium

3. photosynthetic bacterium transformed into chloroplast by evolution

4. eukaryotic plant cell

in the creation of a plant cell - what supports endosymbiosis theory

• size of photosynthetic bacterium an chloroplast

• free DNA inside both

plant read

done

similarities of eukaryotic and prokaryotic cells

what is the role of the DNA in both P and E cells

directs activities of the cell and allows it to reproduce and pass characteristic to progeny

similarities of eukaryotic and prokaryotic cells

even though the function of the DNA is the same is the structure

no

PRO= linear/circular (plasmids)

EUK= chromosomes (23 pairs)

similarities of eukaryotic and prokaryotic cells

do both cells share metabolic pathways

yes

similarities of eukaryotic and prokaryotic cells

give some examples of shared metabolic pathways

especially those related to nucleic acids

• transcription, translation .. (nucleic acid)

• glycolysis

• fermentation

similarities of eukaryotic and prokaryotic cells

do they both have a cell membrane

yes

what is the function of the cell membrane in both cell types

semipermeable barrier

what transport mechanises occur across the membrane

passive transport and active transport

similarities of eukaryotic and prokaryotic cells

do they both have a cell wall?

yes but of different compositions

cell wall of PRO is made out of

peptidoglycan

cell wall of EUK is made out of

cellulose

similarities of eukaryotic and prokaryotic cells

how is the nuclear region similar in both cells

both have genetic material located in a nuclear region surrounded by cytoplasm

key difference noted in the nuclear region

EUK - nuclear membrane present

PRO- DNA free in cytoplasm (no membrane )

similarities of eukaryotic and prokaryotic cells

are ribosomes present in both cells

yes

what is the function of ribosomes

protein synthesis

what ribosomes exist in EUK cells

• free ribosomes

• bound to rough endoplasmic reticulum

• mitochondrial ribosomes

where are free ribosomes located

floating in the cytoplasm

list all the similarities

• DNA

• common metabolic pathways

• semipermeable cell membrane

• cell walls (different composition)

• nuclear region surrounded by cytoplasm

• ribosomes

prokaryotic cells

where is DNA located

free in cytoplasm

prokaryotic cells

what is a nucleoid

region where prokaryotic DNA is located in the cytoplasm

prokaryotic cells

chromosome structure

single circular large chromones - weakly associated with proteins

prokaryotic cells

what is the type of cytoplasm

undifferentiated

prokaryotic cells

what is undifferentiated cytoplasm

absence of organelles, only ribosomes present

prokaryotic cells

cell wall composition

peptidoglycans

prokaryotic cells

how do they move

flagella

prokaryotic cells

what i flagella made of

flagellin

comparison of flagella in PRO and EUK

PRO= flagella made of flagellin

EUK = flagella made of tubline

what is tubline and flagellin

proteins

prokaryotic cells

size comparison

(like the microorganism and bacterium)

similar size to mitochondria and chloroplasts (of eukaryotes - explained by endosymbiosis theory)

what type of cell do bacteria present

prokaryotic cells

eukaryotic cells

how is the DNA organised

as 23 chromosomes surrounded by a nuclear membrane to form the nucleus

eukaryotic cells

DNA association wit proteins :

histones

histones are speciallised proteins bound to

nucleic acids

histones + neucleic acids in EUK produces

an octamer (repetitive structure)

what is the octamer called (histone + DNA)

Nucleosome

what type of cytoplasm does EUK have

differentiated

what does differentiated cytoplasm mean

contains many organelles

what is the plant cell wall composed of

cellulose, pectin and lignin

what is cellulose

repeating polymer of Beta glucose

in cellulose what bonds are between 2 glucoses

glycosidic bond

why is cellulose able to form fibres, why is it rigid

has millions hydrogen bonds (weak individually but strong together)

how do EUK cells achieve mobility

by cilia and flagella

what protein makes up cilia and flagella in EUK

Tubulin

euk is the type of cell presented by ….. not bacteria

the rest of living beings

in eukaryotic cells they contain a nuclear membrane what is contained within the nuclear membrane

nuclear channels

what do nuclear channels do

promote exportation and importation of compounds

is the nuclear membrane similar to the plasma membrane

yes but it contains nuclear channels

which type of microscope was used to get this picture?

transmission electron microscope

(TEM =2D

SEM=3D)

the internal part of the nucleus is composed of what molecule

chromatin