GCSE Edexcel Biology: Topic 1

Animal cells have

Cell membrane
mitochondria
nucleus
ribosomes

Plant cells have

chloroplasts
Cell membrane
Cell wall
mitochondria
nucleus
ribosomes
vacuole

Bacteria cells have

Chromosomal DNA (loop)
cell membrane
cell wall
Flagellum
plasmid DNA
ribosomes

Sperm cells have

Acrosome
haploid nucleus
Mitochondria
streamlines shape
tail

Acrosomes (sperm)

Contains enzyme breaks egg's coat

Haploid nucleus (sperm)

single set of unpaired chromosomes

Mitochondria (sperm)

Releases energy

Tail (sperm)

Propell

Egg cell stuff

cell membrane
haploid nucleus
Nutrients in cytoplasm

Cell membrane (egg)

jelly coat hardens after fertilisation

Nutrients in cytoplasm (egg)

Develops embryo

Ciliated epithelial cells stuff

Cell membrane
epithelial
strands of a substance

Cell membrane (ciliated)

Covers

Epithelial (ciliated)

No hair-like structures

Strands of substance (ciliated)

Contract causes wavy movement

Image =

actual x magnification

How to change focus

Adjust objective lens and focus knob

Magnification =

Eyepiece x objective lens

Light microscope mag

X1500

Light microscope resolution

0.0001nm

Electron microscope mag

X2000000

Electron microscope resolution

0.0000002nm

What does pH do to enzymes

Break bonds

Lock and key theory

Substrate fits active site
Enzyme-substrate complex

What's an inhibitor

Slows enzyme reaction

Increase enzyme concentration

Faster reactions

Enzymes are ...

Proteins

Experiment on enzymes

Iodine on dimples on tile
Amylase on test tube
1cm3 of pH solution
add starch solution
start clock
every 20 secs

Benedicts tests for

reducing sugars

Benedict's positive

Brick red

Benedicts negative

blue

Biurets tests for

Protein

Biurets positive

purple

Biuret's negative

pale blue

Ethonal emulsion tests for

Fats/lipids

Ethonal emulsion positive

Cloudy emulsion

Ethonal emulsion negative

Clear

Iodine tests for

starch

Iodine positive

blue-black

Iodine negative

Yellow-orange

Osmosis

Water molec diffuse from high conc of water molec to low conc of water molec through a partially permeable membrane

Active transport

Movement of dissolved molec through the cell membrane from lower conc to a high conc against conc gradient using energy from resp

Diffusion

Random movement of a substance from a region of high con to a region of low conc