Science Flashcards
What is electric current?
Rate at which electric charge flows
What is an ammeter?
(SI Unit: ampere/A) measures current flowing through an electric circuit. It indicates the amount of electric current flowing past a point per unit time.
- Connected in series
- Negative terminal connected to negative side of cell
What is potential difference/voltage?
Amount of energy needed to move a unit charge to another point
What is a voltmeter?
(SI Unit: volt/V) measures potential difference between two points.
- Connected in parallel to the electrical component
- Positive terminal connected to positive side of cell
What is electrical resistance (R)?
measure of how much the component opposes the electric current (electrical conductors have low resistance)
What is a resistor?
(SI Unit: ohm) reduces the flow of current
- Fixed resistors have fixed and non-adjustable resistance
- Variable resistors (rheostats) is adjustable and has a range of resistances
- Used to keep the current at a safe level to prevent overheating or accidents
- If two resistors are arranged in parallel, the current flow in the circuit increases as there is more than one path for current to flow
Type of enzymes and their functions
Carbohydrases: break down carbohydrates into simple sugars
Proteases: break down proteins into amino acids
Lipases: break down fats into fatty acids and glycerol
Function of stomach
Churns food into smaller pieces.
- Gastric juice with proteases digest proteins
- Thick layer of mucus on stomach lining to protect from acid
- The hydrochloric acid kills harmful microorganisms and is the right condition for proteases to function
- Muscles on both ends ensure that the food does not escape
Function of red blood cells
Transport oxygen around body
Function of plasma
Transports water and dissolved substances (digested food, mineral salts, waste products). It makes up more than half the volume of blood.
Function of white blood cells and platelets
Both serve a protective function.
White blood cells protect against infection.
Platelets form blood clots so blood cells cannot pass through. Prevents severe bleeding and microorganisms from entering wounds.
Parts of male reproductive system
Sex glands: produce nutrient fluid to nourish the sperm
Sperm ducts: carries sperm from testes to urethra
Urethra: tube for sperm to pass through during ejaculation (urine also exits here)
Testis: produces sperm and male sex hormones (to control sexual development)
Penis: deposits semen into vagina during ejaculation
Parts of female reproductive system
Oviduct: Tube that the egg is released into from ovary and connects to uterus, and where fertilisation occurs.
Ovary: produces eggs and sex hormones
Uterus: a muscular organ where the embryo develops into a fetus during pregnancy, where the lining thickens to prepare for implantation and breaks down if there is no fertilisation.
Cervix: the opening of the uterus connecting it to the vagina
Vagina: where sperm are deposited; birth canal
Menstrual cycle
Both ovaries take turns each month to to release an egg cell.
Day 1-5: Menstruation occurs (Breaking down of uterus lining)
Day 6-9: Uterus lining thickens preparing for implantation
Day 10-15: Egg is released into oviduct (fertile period)
Day 16-28: Uterus lining continues to thicken. Menstruation will occur after if there is no fertilisation.
Sperm cells survive in the uterus for up to five days.
What can substance abuse during pregnancy lead to?
Premature babies, low birth weight of baby, physically and intellectual challenges of baby
