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Biology Paper 1(3) - advance info revision - Coggle Diagram
Biology Paper 1(3) - advance info revision
2.1 - supplying the cell
osmosis
high water potential --> lower water potential, down the concentration gradient
in plants and animal cells
diffusion of water molecules across permeable membranes
active transport
energy required - ATP from respiration
carrier proteins in the cell membrane
low concentration --> high concentration, against the concentration gradient
diffusion
define - the net overall movement of particles from a region of high concentration to a region of low concentration - moving down the concentration gradient
end when concentration is the same everywhere, the concentration gradient is 0
particles in gas or a solution coastally moving
passive process no energy transferred
glucose and oxygen diffuse from blood into cells that need them
rate dependent on: - the distance the particles must move - the concentration gradient - the surface area
stem cells
undifferentiated
can develop into any cell desired
used during body development, growth and repair
2 main types of stem cell
embryonic
ability to differentiate into all cell types, found only in embryos, ethical issues
adult
found in brain, bone marrow, skin, liver - only able to differentiate into a few types of cell
in plants - certain parts continue to grow their entire life - found in meristems
cell differentiation
adaptations to be more effective at job - sperm cell, fat cell, red blood cell, ciliated cell, palisade cells
cells differentiate to become specialised for one job - make organism more effective
mitosis
2 identical daughter cells - increases the number of cells in a multicellular organism
process of growth and division - cell cycle - DNA replication, movement of chromosomes, cytokinesis and growth of a daughter cell
body cells divide to replace worn out cells and replace damaged tissue
diagrams p.65
1.2 - what happens in cells
enzymes
biological
catalysts
enzymes have and active site
, specific substrates fit into the active site using the lock and key method
used to build large molecules from smaller ones and break down large molecules to smaller ones
transcription and translation
transcription
creates mRNA
mRNA moves out of the nucleus
single strand of
mRNA
created to travel
mRNA travels to ribosomes in the cytoplasm, where proteins will be made
proteins are made in
translation
, the ribosome translates the mRNA triplet code to an amino acid
amino acids join together to
make a protein
DNA
a polymer made up of
nucleotides
joined together
complementary nucleotide base pairing, A-T, C-G
phosphate - deoxyribose - base
double helix
enzyme reactions
optimum temperature then denaturing
optimum PH then denatured
ROR dependent on many factors including
temperature and PH
also dependent on enzyme and substate concentration - when they are used up the reaction ends
3.2 coordination and control
the menstrual cycle
controlling reproduction
negative feedback
hormones
using hormones to treat infertility
uses of plant hormones
plant hormones
2.2 - the challenges of size
circulatory system
heart and blood
exchange and transport
plant transport systems
factors affecting transpiration
transpiration stream