Topic 1

role of the nucleus

• contains DNA which codes for proteins

• site of transcription where mRNA is made

a channel protein spans the membrane what type of r groups will be found near the pore that molecules can pass through

• polar or charged that are hydrophilic

• as they are near the water environment inside and outside of the cell

what does a nucleus contain

• nuclear pore

• nuclear envelope

• chromatin

• nucleoplasm

• nucleolus

nuclear envelope

double membrane with pores

nuclear pore

allows mRNA and ribosomes to leave the nucleus

chromatin

DNA coiled around histone proteins for protein synthesis

nucleolus

rRNA synthesis

structure of a nucleus

mitochondria role

produces ATP in aerobic respiration

what does a mitochondria contain

• matrix

• cristae

• 70S ribosomes

• DNA

• outer/ inner membrane

matrix

jelly like substance containing lipids and proteins

cristae

• folding of the inner membrane

• site of ATP synthesis

• increase the surface area

advantage of mitochondria being cylindrical

increases surface area to volume ratio, reducing diffusion distance for aerobic respiration

structure of a mitochondria

rough endoplasmic reticulum

ribosomes on outer surface making it bumpy and cisternae transport proteins made

smooth endoplasmic reticulum

made of membranes that lack ribosomes

endoplasmic reticulum

• flattened sacs

• double membraned cisternae leading on from nuclear envelope

endoplasmic reticulum structure

ribosomes role

• site of protein synthesis

• 2 different sizes 70s and 80S

ribosome structure

• made up of large and small subunit

• made up of rRNA and proteins

lysosmes role

waste disposal unit

lyosome structure 

vesicles with double membrane and proteins and digestive enzymes

chloroplast role

site of photosynthesis

what does chloroplasts contain

outer membrane, inner membrane, stroma, thylakoid, lamella, granum, inter membrane space, 70S ribosomes

stroma

fluid filled containing products of photosynthesis

thylakoids

membrane bound disks where photosynthesis takes place

granum

stack of thylakoids

lamella

connects thylakoids

plasmodesmata

hole in cell wall and membrane filled with cytoplasm

allows diffusion between cells

plant cell structure

animal cell structure

centrioles

2 rings of micro tubules outside nucleus, organise micro tubules that make the spindle in cell division

not present in plants

vacuole

fluid filled sap surrounded by tonoplast membrane

cell wall for prokaryotes made of

peptidoglycan

prokaryotes

DNA not membrane bound

cell wall for fungi

chitin

what ion is cell wall strengthened by

calcium

mesosmes

make ATP in prokaryotes

name 4 structures that some prokaryotes contain but not all

slime capsule, plasmids, flagellum, pili

smooth endoplasmic reticulum function

to produce and transport lipids

how are products of photosynthesis stored in chloroplasts

as starch grains and lipid droplets

plasmodesmata

gap in cell walls and cell membranes of adjacent plant cells filled with cytoplasm

what nucleic acids may be found in a virus

DNA or RNA

stroma

contains enzymes for light independent reactions of photosynthesis

mesome

folding of cell membrane found only in prokaryotes 

structure of DNA in prokaryotes

circular and not bound to proteins

structure of rough endoplasmic reticulum

flattened sacs called cisternae attached to the nuclear envelope, 80s ribosomes are attached to the cisternae

describe structure of a virus

nucleic acid surrounded by a protein coat

describe the structure and function of the nuclear envelope

double membrane that separates the contents of the nucleus from the cytoplasmk

key characteristics of all prokaryotic cells

free DNA in the cytoplasm called nucleoid

describe the structure of ribosomes

2 subunits made of rRNA and proteins

structure of permanent vacuole

fluid filled sac surrounded by membrane called the tonoplast

what does the matrix in the mitochondria contain

enzymes

function of the golgi body

modify proteins and pack them into vesicles to either export to cell membrane surface or to use in cell

cell theory

new cells form from existing cells which are the fundamental unit of organisms

what is the prokaryote cell wall made from

peptidoglycan

why are cristae needed

to increase surface area of inner membrane

which 2 parts of mitochondria indicate organelle was once bacteria

• circular DNA to self replicate

• 70S ribosomes to make own proteins

explain how you would identify cardiac muscle tissue 

cells are found only in the heart, they are striated but don’t form long fibres 

explain how you would identify skeletal muscle tissue 

made of long parallel cells arranged to form fibres, striated, found attached to bones

in the endosymbiotic theory what is the benefit to the eukaryotic cell

gains the function of aerobic respiration and photosynthesis

explain how you would identify smooth muscle tissue 

cells form no uniform shape and are unstriated, they are found throughout the body

golgi body structure 

cisternae, lumen, transface, cisface, newly forming vessicle, secretory vessicle

what does golgi body do to vessicle

receives them from endoplasmic reticulum

role of pilli

lets prokaryotes stick to eachother or a host

endosymbiotic theory

eukaryotes are evolved from prokaryotes

cell theory

all living organisms are composed of cells, a cell is the basic unit and cells arise from pre-existing cells

endocytosis

enveloping the membrane of other organelles

how does endosymbiosis work overview

1. variation in prokaryotes means that 1 may be aerobic bacteria

2. endocytosis occurs and a large cell engulfs the aerobic bacteria but isn’t digested so they work together

3. over time bacteria becomes mitochondria

advantage of endosymbiosis to chloroplasts/mitochondria

• protection

• raw materials supplied to them

• provides ideal conditions for reactions

advantage of endosymbiosis to eukaryote

• initially temporary benefit but evolutionary advantage

• provided ATP so internalised energy store

• photosynthesis so internalised nutrient supply

endosymbiosis method

• extensions of membrane forms vesicles

• organelles engulfed

• bacteria cell membrane surrounds organelles membrane forming double membrane

• vessicle formed and moved through the cell taking in organelles

• organelles eventually permanent feature of cell

to find the overall magnification

eyepiece lens X objective lens

why may 2 pictures of a mitochondria look different

• they are cut across different planes

• they vary in shape

magnification equation

magnification= image/ actual

how would you identify squamous epithelial tissue

cells are thin and found lining organs

how would you identify smooth muscle tissue

cells form no uniform shape, are unstriated, found throughout the body

facts that support mitochondria and chloroplasts

like prokaryotes they :

• have free DNA

• have 70s ribosomes

• divide by binary fission

• affected by antibiotics

link the properties of cardiac muscle to its function

• cardiac muscle allows heart to contract so doesn’t tire and acts involuntary

• striated so have medium power

3 categories of tissue found in animals

epithelial, muscle, connective

in the endosymbiotic theory what is the benefit to the eukaryotic cell

protection from external environment, substances can flow from the mitochondria to the chloroplast

link the properties of skeletal muscle to its function

• skeletal muscles allow bones to move, therefore there are voluntary muscles

• due to long bands of cells it has a high power

• due to high power it tires easily

describe the structure of connective tissue

contains fibres of collagen and elastic

cells

basic unit of a living thing

tissues

different cells work together for a specific function

organs

different tissues that work together for a specific function

organ systems

different organs that work together to support a whole system

organism

different systems work together to support the whole organism 

different types of epithelial tissue

squamous, cuboildal, cilliated

epithelial tissue

• continuous layers that line external/ internal surface

• cells sit on basement membrane of collagen and other proteins

• maybe have protective/ secretory functions and nerve endings

squamous tissue

e.g walls of alveoli

flattened cells used for diffusion

cuboidal epithelial tissue

e.g salivary glands

1 cell thick

ciliated columnar epithelial tissue

e.g in trachea

substances move through them

columnar epithelial tissue with micro villi

for absorption in the small intestine 

protein

biological molecules, all complex polymers made from amino acids and monomers

polypeptides

chain of amino acids

zwitterion

at a pH of 7 the amino group is positively charged and the carboxyl group is negatively charged so overall neutral