B4 Flashcards
what is respiration?
transferring energy from the breakdown of glucose
how do plants make glucose
photosynthesis
how do animals make glucose
breaking down biomass
what is ATP
it stores the energy that is used for essential processes like breaking and making molecules, active transport and contracting muscles
why does cellular respiration occur continuously in all living cells
bcs organisms need the energy to survive
is respiration exothermic or endothermic
exothermic because it transfers energy to the environment
what is aerobic respiration
- plenty of oxygen available
- most efficient way of transferring energy from glucose
equation for aerobic respiration
glucose and oxygen –> carbon dioxide and water
where does aerobic respiration take place in eukaryotic cells
mitochondria bcs it contains most of the enzymes needed to control aerobic respiration reactions
how can u work out rate of respiration from substrate practical
volume of CO2/time
what is anaerobic respiration
respiration without oxygen
when does anaerobic respiration happen
when theres little or no oxygen available
where does anaerobic respiration
cytoplasm
anaerobic respiration in human cells
during vigorous exercise, he body cant supply enough
anaerobic respiration in plant cells
when the soil is waterlogged, therell be no oxygen for the roots so anaerobic
anaerobic respiration in bacterial cells
when bacteria is somewhere with a lack of oxygen
animals anaerobic respiration equation
glucose –> lactic acid
plants and some microorganisms anaerobic respiration equation
glucose –> ethanol and carbon dioxide
aerobic and anaerobic points for comparison:
conditions, input, outputs and ATP yield
conditions, input, outputs and ATP yield
aerobic: oxygen present, glucose and oxygen, carbon dioxide and water, 32 ATP per molecule of glucose
anaerobic: lack of oxygen, glucose, lactic acid/ethanol and carbon dioxide and 2 ATP per molecule of glucose
what is in the cell cycle
interphase and mitosis
what does the cell cycle do?
makes new cells for growth and repair
what is mitosis used for
to grow (by dividing) or replace cells that have been damaged
how to estimate number of cells after multiple divisions of mitosis
2^n
n=number of divisions
what could affect the total number of cells
cells could die or lack of food meaning the cells could divide at slower rate
what is cancer
- if theres a mutation in the gene that controls cell division, a cell may divide uncontrollably, creating a tumour
when does it become cancer
if a tumur invades and destroys surroundning tissue
how do light microscopes work
by passing light through the specimen
how do electron microscopes work
they use a focused beam of electrons
what can we see with electron microscopes
smaller things in detail like the internal structure of mitochondria and chloroplasts
how can we use microscopes to see the stages of mitochondria
- chromosomes get stained
- cells are viewed on a squash
- cells get taken from the root tip where the most cells divisions
total magnification
eyepiece lens magnification x objective lens magnification
magnification
measured size/acual size
what is meiosis
a form of cell division which produces four non-identical, haploid sex cells or gametes
what is a specialised cell
a cell that is able to divide to produce any type of specialised cell
- embryonic cells
example of specialised cell
blood and nerve cells
what is differentiation
the process of stem cells becoming specialised
when do cells become specialised in humans
eight cell stage
adult stem cells
- only certain places, like bone marrow
- only make certain types of cells
how do cells become specialised
stem cells switch off the genes they don’t need during development so active genes can produce proteins for the type of specialised cell
what are meristem cells
meristems produce unspecialised cells
- they can differentiate to make any type of cell as long as the plant lives
unspecialised cells in plants
xylem and phloem
benefits of stem cells in science
- used to replaced cells damaged by injury or disease
- can crate new cures
- new cardiac muscle cells transplanted into someone with heart disease
risks of stem cells in science
- stem cells divide quickly and if it cant be controlled in the patient, it can lead to a tumour
- viruses live inside cells and can be transported to the recipient which makes them sicker
ethical issues in medicine
- the embryos get destroyed but its still a potential life
- using stem cells in medicine and science is mostly regulated by the government
