biology big to small Flashcards
what is a cell
the smallest functional unit in a living organism
function of a nucleus
controls the activity of the cell - making proteins
nucleus contains?
chromosomes - strands of dna which carry genes - each gene codes for a protein
function of cell membrane
boundary between the cytoplasm and surrounding cells - controls what comes in and out of the cell = selectively permeable
function of cytoplasm
jelly like liquid where chemical reactions occur
function of mitochondria
carries out aerobic respiration - producing ATP
function of ribosomes
synthesise proteins from amino acids
function of chloroplasts
absorbs light energy to make food by photosynthesis
what do chloroplasts contain
chlorophyll
what cell does not have a nucleus
red blood cells
what are some organelles in a cell
mitochondria, chloroplasts, ribosomes & nucleus
what is the largest organelle in a cell
nucleus
which organelle is found in the cytoplasm of all living cells
mitochondria (needed for respiration)
what do all cells start as
stem cells
how do stem cells become specialised cells
they develop new features
what is the function of red blood cells
transport oxygen in the blood
features of red blood cells
• contain haemoglobin (protein)
• haemoglobin binds to & transports oxygen
• no nucleus so more space for haemoglobin
• biconcave disc shape ( larger surface area - more oxygen can enter & leave )
function of sperm cell
transport male genetic material to the egg cell
features of a sperm cell
• flagellum helps to swim
• many mitochondria - energy for swimming
• acrosome - digests jelly layer surrounding egg cell
leaf cell is called
palisade
function of palisade
carries out photosynthesis
features of palisade cell
• chloroplasts - trap light energy
• tall and thin cells
• pack tightly to allow better light absorption
what are biological molecules
carbohydrates, proteins and lipids (fats)
what are carbohydrates made of
carbon, hydrogen & oxygen
what are lipids (fats) made of
carbon, hydrogen & oxygen
what are proteins made of
carbon, hydrogen, oxygen & nitrogen
what are the functions of lipids
• thermal insulation
• electrical insulation - around nerve cells
• energy storage
• buoyancy in marine animals
what are the functions of proteins
• control chemical reactions - enzymes
• transport eg haemoglobin
• combat disease eg antibodies
• messenger molecules - hormones
