BMAT - Biology
Card Set Information
BMAT - Biology
What is the structure of a bacterium?
Cell membrane, surrounded by cell wall
of DNA (no nucleus)
What are the four types of pathogens?
reproduction (binary fission)
Can damage cells
Every invading cell has
When foreign antigen is encountered →
produced = immunity
Bacteria can mutate=
, those that are resistant survive
Resistant strains can't be treated by antibiotics, e.g.
(causes wound infections), resistant to
Overuse of antibiotics=more resistance.
Resistance is becoming more common
What is a catalyst?
A substance that increases the rate of reaction without undergoing any permanent change itself.
What is respiration?
Involves many reactions, all of which are
Process of releasing energy form
, which goes on in every cell.
Aerobic= with oxygen
Respiration used to build
molecules, to keep body
Anaerobic is incomplete breakdown of glucose
Produces lactic acid, does not release as much energy
Glycogen converted back to glucose during exercise
Active transport in gut
When high conc. of nutrients in gut, they diffuse naturally into blood.
When low conc. of nutrients in gut but high in blood, active transport is used.
This stops us from starving.
Tissues can include more than one type of cell
Organs can include more than one type of tissue
Enzymes and digestion
Amylase breaks down starch into maltose (saliva, pancreas, small intestine)
Protease breaks down proteins into A.A (made in stomach -pepsin-, pancreas, small intestine)
Lipase breaks down lipids into fatty acids and glycerol (made in pancreas and small intestine)
: breaks down food
: produces bile (neutralises acidic stomach acid and emulsifies fats)
: stores bile
: Where nutrients are absorbed
: water is absorbed
: stores faeces
: Diaphragm and intercostal muscles contract, ribs move up and out, pressure decreases
: Diaphragm and intercostal muscles relax, ribs move down and in, pressure increases
: help people to breathe, work by pumping air into lungs, can destroy alveoli.
Heart blood flow
Too much clotting can cause stroke and deep vein thrombosis.
Haemophilia is a genetic disease where blood doesnt clot because clotting factor is missing. This can be injected.
You need to match the blood groups to transfuse.
A, B, AB, O - refer to antigens on surface of RBC's.
RBC's have A or B antigens (or neither, or both)
If anti-A/B antibody meets A/B antigen, agglutination occurs.
O has no antigens - can donate to anyone.
Adrenaline affects heart rate (fight or flight mode)
A group of cells called pacemakers produce small electric currents, which cause heart to contract.
Sino atrial node stimulates the atria
Atrio ventricular node stimulates ventricles
SAN stimulates AVN.
Artificial pacemakers used if cells don't work.
Electrocardiograms (ECG) used to show electrical activity of heart.
Echocardiogram are ultrasounds of heart.
Sense organs and receptors
: Light receptors
: sound receptors
: smell receptors
: taste receptors
: touch receptors
Messages from CNS (brain and spinal chord) are sent to effectors (muscles)
: send signals from receptors to CNS
: carry signals from sensory neutrons to motor neurone
: carry signal from CNS to effector
Electrical impulses pass along axon.
Myelin sheaths increase speed of signals.
Have branched endings - dendrites
: One long dendrite carries signal from receptors to cell body.
Short axon carries signal from cell body to CNS.
: Short dendrites carry signal from sensory neutron to cell body.
Short axons carry signal form cell body to motor neurons.
: Short dendrites carry signal from CNS to cell body
Long axon carries signal from cell body to effector cell.
Pain receptors are stimulated
Impulses travel along sensory neutron
Impulses pass through relay neutron via synapse
Impulse travels through motor neuron via synapse.
When impulse reaches muscle, it contracts.
Reflexes improve chance of survival.
Drugs (like ecstasy) block serotonin receptors.
Serotonin conc increases - mood enhancer.
Hormones vs nerves
Hormones travel in blood stream
Hormones are slow nerves are fast
Hormones have long lasting effects, nervous do not
Nerves act on specific area, hormones more general
Homeostasis is about maintaining a constant internal environment
Negative feedback is used to bring levels back to normal e.g. water.
: released from adrenal glands. Responsible for fight or flight mode. Triggers glycolysis in liver and muscles.
: Released from beta cells in pancreas. Reduces glucose levels.
: Increases blood glucose, released from alpha cells.
: released from pituitary gland. Inhibits loss of water. Acs on lower parts of nephron.
: growth, puberty, hair growth.
Menstrual cycle hormones
: Produced in ovaries. Inhibits FHS, overrides progesterone at the end of pregnancy. Buildup of uterus.
: maintains the lining of the uterus. Inhibits FSH and LH. Causes breast development
: Released by pituitary gland at start of menstrual cycle. Stimulates development of primary follicles which secrete oestrogen.
: Produced by pituitary gland at around day 12 of cycle. Causes release of egg cell.