cell structure and organisation Flashcards
what are the properties and functions of the cell surface membrane?
p=partially permeable
f= -it controls the movement of substances in and out of the cell
-separates the cell contents from the external environment
what are the properties and functions of the cytoplasm?
p= -a jelly-like substance mostly made of water
-contains all dissolved substances like carbohydrates, lipids, proteins, etc.
-organelles are suspended within the cytoplasm
f=where most cellular reactions occur (eg, glycolysis, translation)
what are the properties and functions of the nucleus?
p= -contains DNA (deoxyribonucleic acid)
-in humans, the nucleus of non-sex cells contains 46 chromosomes (23 chromosomes inherited from the father, 23 chromosomes inherited from the mother)
f= -controls cellular activities like growth and repair
-when preparing for cell division. DNA condenses to form chromatin threads that further coil and are packed to form chromosomes
-genes carries instructions to synthesise proteins for a specific function of the cell
what are the properties and functions of the cell wall?
p= =fully permeable
-plant cell walls contain cellulose fibres which criss-cross to form a very strong outer layer for the cell
-found in all plant cells
f= -protects and supports the cell
-prevents the cell from bursting when excess water enters
-gives the plant its regular shape
what are the properties and functions of the chlroplast?
p= -oval-shaped organelles bound by a double membrane
-contains chlorophyll which trap light for photosynthesis to occur
f= photosynthesis: light energy is absorbed by chlorophyll to convert carbon dioxide and water into glucose for the plant. oxygen is released as a by-product
what are the properties and functions of the vacuole?
p= -a fluid-filled space bound by a single membrane
-plant cells have one large permanent vacuole located centrally
-animal cells have many small vacuoles commonly known as vesicles
f= -vacuoles store cells sap which contains glucose, water, dissolved mineral salts, and other substances. helps keeps the plant cell firm
-vesicles are mostly used to transport substances within and out of the cell (sometimes used to temporarily store nutrients and water)
what are the properties and functions of the mitrochondrion?
p= -rod-shaped organelles bound by a double membrane
-numerous in cells with high energy requirements (heart, liver, muscle)
f= -site of cellular (aerobic) respiration
-glucose is broken down to release (not produce) energy
what are the properties and functions of the ribosomes?
p= -contains of two ribosomal subunits
-freely floating in the cytoplasm
-round to the rough endoplasmic reticulum
f= site of protein synthesis
what are the three basic structures in a cell?
cell surface membrane, cytoplasm, and nucleus
what are the structures that are only found in the plant cell?
cell wall, chloroplast, and a large central vacuole
what are structures common to both animal and plant cells?
mitochondrion and ribosome
what are the structures and functions of the rbc?
s=f
lack nucleus and other organelles=allows rbc to pack more haemoglobin per cell to transport oxygen more efficiently around the body
circular, biconcave shape=increase surface area to volume ratio for rapid diffusion of oxygen into or out of the cell
lack mitochondrion=to ensure rbc do not respire the oxygen they are meant to transport
what are the structures and functions of the root hair cell (plant cell)?
s=f
long and narrow=increase surface area to volume ratio for efficient absorption of water and mineral salts
no waxy cuticle, concentrated cell sap=provides a steep water potential gradient for water to move quickly into the root hair cell
contains numerous mitochondria=provides energy required for active transports of ions into the cell
what are the structures and functions of the xylem vessel(plant cell)?
s=f
long hollow tubes with no cross walls and protoplasm=continuous and smooth passage of water to transport water and mineral salts
lignin deposit on wall=supports the plant and prevents the vessel from collapsing
