biology Flashcards
how does the body defend itself from the entry of pathogens
**Skin **
* acts as a barrier
* produces sebum / oil that **repels pathogens **
* platelets in blood form clots / scab at wounds * scabs prevent pathogen **entry at wounds Eyes **
* produce tears
* tears contain enzymes to kill bacteria/low pH
* tears are antiseptic Breathing System * Cells lining the nose/trachea / **bronchi produce mucus **
* mucus is sticky * (mucus) traps bacteria
* cilia/ciliated cells move mucus to be removed
**Stomach **
* contains (hydrochloric) acid
* acid/low pH kills bacteria
* in food or in swallowed mucus
Metabolic reactions: * Amino acids are used to synthesise proteins * Glucose is converted to glycogen * Glucose is broken down in respiration Importance * Glycogen acts as a store of glucose in muscles for respiration * Energy transferred/released from respiration in cells is used by the organism for further metabolic reactions * Link to uses of energy from respiration: Need energy to synthesise new molecules, carry out active transport, heat energy – maintain body temp * Amino acids are needed to make proteins which are needed for: enzymes to catalyse reactions, hormones, antibodies, growth and repair of tissues. Removal of waste products: * Water from breakdown of glucose/ respiration is removed by the lungs
c reactions
* Link to uses of energy from respiration: Need energy to synthesise new molecules, carry out active transport, heat energy – maintain body temp
* Amino acids are needed to make proteins which are needed for: enzymes to catalyse reactions, hormones, antibodies, growth and repair of tissues.
Removal of waste products:
* Water from breakdown of glucose/ respiration is removed by the lungs during exhalation, as sweat from skin, and in urine via the kidney
* Carbon dioxide from the breakdown of glucose/ respiration is removed by the lungs during exhalation
* Excess amino acids are deaminated to form ammonia in the liver. Ammonia is converted to urea for safe excretion in urine via the kidney.
