national 5 biology unit 1

nucleus

controls cell activity

cell membrane

controls entry + exit of substances

cell wall

supports + strengthens the cell

cytoplasm

site of chemical reactions

vacuole

water storage

chloroplast

site of photosynthesis

mitochondria

site of aerobic respiration

ribosomes

site of protein synthesis

passive transport

movement of molecules from a high concentration to a low concentration without energy (osmosis/diffusion)

active transport

movement of molecules from a low concentration to a high concentration against the concentration gradient

diffusion

movement of molecules down a concentration gradient from a higher to a lower concentration

osmosis

movement of water from a high concentration to a low concentration through a selectively permeable membrane

animals cells in 1.7% salt solution

lose water by osmosis and shrink

animal cells in high water concentration

gain water by osmosis and burst

plant cells in low water concentration

lose water by osmosis and become plasmolysed

plant cells in high water concentration

gain water by osmosis and become turgid

plant cell

cell wall, cell membrane, cytoplasm, nucleus, chloroplasts, vacuole, mitochondria, ribosomes

animal cell

cell membrane, cytoplasm, nucleus mitochondria, ribosomes

fungus cells

cell wall, cell membrane, cytoplasm, nucleus, vacuole, mitochondria, ribosomes

bacterium cell

cell wall, cell membrane, cytoplasm, ribosomes, plasmids

what do all cells share?

cell membrane, ribosomes

gene

section of DNA that codes for a protein

sequence of bases

sequence of amino acids which determines function and structure of the protein

DNA

molecule made of nucleotides containing genetic information

protein synthesis

• double helix dna unwinds + unzips along a gene

• mRna creates complementary copy on DNA code

• mRna seperates from DNA, leaving through holes in the membrane

• mRna atatches to ribosome to create proteins

enzymes

biological catalysits that speed up chemical reactions in cells

factors affecting enzyme activity

temperature, pH, concentration

types of proteins

structural, elastin, enzyme, hormone, antibodies

structural protein

collagen

elastin protein

elasticity to skin

enzyme protein

amylase

hormone protein

insulin

antibodies protein

fight infection

activation energy

energy required for a chemical reaction to occur

protein synthesis definition

build up of small to large molecules

protein synthesis equation

glucose -(amylase) -> starch

protein degradation equation

starch -(amylase) -> maltose

protein degradation definition

large molecules broken down to small molecules

genetic engineering

transfer of genes to another organism of a different species

stages of genetic engineering

• extract plasmid from bacteria

• open plasmid with enzymes

• identify + remove gene from chromosome

• insert gene into plasmid

• insert plasmid into a bacterium

• grow large numbers of bacteria

aerobic respiration

respiration where oxygen is present

anaerobic respiration

respiration where oxygen is not present

which type of respiration is the most efficient?

aerobic respiration as glucose is completely broken down and a lot of ATP is produced

basic equation for respiration

glucose + oxygen → carbon dioxide + water

fermentation in plant/yeast cells

glucose -> pyruvate -> ethanol + carbon dioxide

effect of lactate on muscle tissues

muscle fatigue

similarities / differences between fermentation in plant and animals cells

• both types of fermentation have anaerobic conditions

• fermentation is reversible in animal cells and irreversible in plant cells

• 2ATP produced in both

fermentation in animal cells

glucose -> pyruvate -> <- lactate

fermentation

breakdown of glucose in the absence of oxygen