biology mock

Parts of the circulatory system

heart, blood vessels, blood

chambers of the heart

right atrium, right ventricle, left atrium, left ventricle

valve

prevents blood from flowing backwards

what has valves

veins (atrium and ventricles are separated by one)

which ventricle is thicker and why

the left as it has to pump blood around the entire body

arteries direction of blood flow

away from the heart

veins direction of blood flow

towards the heart

coronary arteries

supply the heart muscle with oxygen and nutrients

arteries structure

thick elastic/muscular walls, narrow lumen

arteries role

carry blood at a very high pressure

capillaries structure

permeable walls which are one cell thick for a short distance diffusion

capillaries role

exchange nutrients and waste products with tissues

nutrients exchanged by the capillaries

glucose, amino acids

waste products exchanged by the capillaries

carbon dioxide, urea

vein structure

thin walls, wide lumen

vein role

carry blood from the body back to the heart at a low pressure

red blood cells role

carry oxygen from lungs to tissues

Haemogoblin

large pigmented protein which binds to oxygen

red blood cells structure

no nucleus, biconcave shape

white blood cells role

defend against infection/pathogens

platelets role

to clot the blood when a blood vessel breaks

plasma role

carry substances and cells around the body

plasma structure

small, flexible

DNA structure

double helix

dna location

chromosomes in the nucleus

gene

small section of dna which codes for a specific protein

dna

polymer of four nucleotides

dna nucleotide structure

phosphate, sugar, base

bases

a and t, c and g

protein synthesis

formation of proteins

protein synthesis steps

transcription and translation

transcription

dna molecule unzipped to create a template in the form of mRNA, template leaves the nucleus

translation

mRNA template guides translation of ribosomes onto cytoplasm

mitosis

DNA divides into two

mitosis steps

DNA condenses to form chromosomes,chromosones line up along centre of cell,cell fibres pull the two arms of each chromosones apart,entire cell divides to form 2 daughter cells

Cytokinesis

division of the cytoplasm to form two separate daughter cells

cell differentiation

the process by which a cell becomes specialised

Specialised cells

Cells that are adapted to carry out a particular function

stem cells found in animals

embryonic, adult

features of stem cells

can divide by mitosis and differentiate into specialised cells

embryonic stem cells

can differentiate into any type of cell

adult stem cells

can only form into cells that are in the tissue surrounding them

meristems

where stem cells are found in plants

cell cycle steps

cell growth, mitosis, cytokinesis

factors which affect rate of diffusion

temperature, surface area, concentration gradient

active site

the region on the enzyme where the substrate binds

induced fit model

the enzyme active site slightly changing shape to bind to the substrate

enzyme

biological catalyst made from a long chain of amino acids

respiration

release of energy from sugar molecules, supplies ATP

respiration reaction

exothermic

respiration equation

glucose + oxygen = carbon dioxide + water

Anaerobic respiration equation

glucose = ethanol + carbon dioxide

anaerobic respiration

respiration that does not require oxygen and produces lactic acid

aerobic respiration

respiration that requires oxygen

photosynthesis location

takes place in the chloroplast

Photosynthesis equation

Carbon dioxide + water = glucose + oxygen

photosynthesis reaction

endothermic

glucose formula

C6H12O6

uses of glucose in plants

making cellulose, making starch, making lipids, making amino acids

Chlorophyll role in photosynthesis

capture light for photosynthesis

factors which affect photosynthesis

temperature, carbon dioxide concentration, light intensity

lipids

fats and oils formed from fatty acids and glycerol

lipids role

to insulate and regulate body temperature, to provide energy

proteins

long chains of amino acids

carbohydrates

polymers of starch or simple sugars like glucose

test for sugar

Benedict's solution

benedicts solution positive result

blue to brick red

Test for starch

Iodine

iodine positive results

orange to blue black

Test for protein

Biuret solution

biuret solution positive result

blue to lilac/purple

test for lipids

emulsion (ethanol and distilled water) test

emulsion positive result

turns cloudy

osmosis

diffusion of water from an area of high to low concentration across a selectively permeable membrane

diffusion

movement of molecules from an area of higher concentration to an area of lower concentration

active transport

movement of dissolved molecules from an area of lower to higher concentration through the cell membrane

xylem role

transport water and mineral salts

phloem role

transport sucrose and amino acids

xylem process

Transpiration stream

phloem process

translocation

xylem structure

no cytoplasm, impermeable to water, tough walls containing lignin

Translocation

the transport of a dissolved material within a plant

transpiration

loss of water from leaves by evaporation

factors affecting transpiration

increase in temp, air movement and light intensity increases transpiration rate

root hair cells structure

large surface area, contain lots of mitochondria,

eukaryotic cells structure

contain a nucleus, mitochondria, ribosomes

prokaryotic cell structure

contain no nucleus, DNA is in the cytoplasm, ribosomes, no mitochondria

synapse

gap between neurons which releases chemicals

parts of the central nervous system

brain and spinal cord

receptor role

to detect a stimulus

sensory neurone role

to transfer a signal from a receptor to the CNS

motor neurone role

to transfer a signal from the CNS to an effector

relay neurone role

to transfer a signal from a sensory neurone to a motor neurone

reflex

an automatic response to a stimulus

reflex arc

stimulus, receptor, sensory neurone, relay neurone, motor neurone, effector, response

cerebral cortex role

consciousness, memory, hearing and vision

cerebellum role

muscle coordination, balance

medulla role

unconscious activites eg heart and breathing rate

hypothalamus role

hunger and thirst, body temperature

methods scientists use to study the brain

scanning, stimulate different parts, study people with brain damage