B1 Flashcards
what is the structure of the cell membrane
phospholipid bilayer
what is the function of the cell membrane
controls movement of substances in and out of the cell
what is an adaptation of the cell membrane that allows it to carry out its function
selectively permeable
describe the phospholipid bilayer
hydrophillic head
hydrophobic tails
bilayer (two layers where legs in the middle and heads top and bottom)
what does the cytoplasm mainly consist of
mainly composed of water, salts and proteins
what is inside the cytoplasm
everything contained within the cell and outside the nucleus
what is the function of cytoplasm
provides a medium for cell activities and chemical reactions to take place
what is the structure of the nuclear envelope
double membrane perforated with pores
what is the structure of the nucleolus
densest part of nucleus
what is the function of the nucleolus
synthesises ribosomal RNA (rRNA)
what is the function of the nucleoplasm
medium for chemical reactions to occur
what is the structure of chromatin
mass of long thread-like structures made up of DNA and protein
what is the function of chromatin
controls cell activities like cell division
what is the function of the nucleus
- encloses genetic material in the form of DNA
- controls cell activities such as cell growth and repair of worn-out parts
- essential for cell division
what is the structure of the mitochondria
smooth outer membrane, highly folded inner membrane with infoldings (cristae)
what is the purpose of the mitochondria structure
to increase surface area
what is the function of the mitochondria
synthesises ATP from the oxidation of food substances via aerobic respiration to provide energy for cell activities
why does the mitochondria synthesise ATP
to provide energy for cell activities
what is the cell wall composed of
composed of cellulose
what type of cells can you find the cell wall in
plant and prokaryotes
what does the cell wall do
o supports and defines shape of plant cell
o protects cell from mechanical injury and invasion
o prevents excessive uptake of water
what is the structure of a chloroplast
double membrane (chloroplast envelope)
what are the components of the chloroplast envelope
inner membrane
outer membrane
what occurs in the chloroplasts
site of photosynthesis
what is photosynthesis
the process by which plants make food
describe photosynthesis
uses water and carbon dioxide as raw materials to produce oxygen and glucose in the presence of light
converts solar energy to chemical energy
what is the vacuole structure
large central vacuole containing cell sap surrounded by tonoplast (single membrane)
what is the vacuole function
o storage of organic compounds and inorganic ions
o disposal site for toxic metabolic by-products
o contains pigments
o cell growth and elongation as water accumulates
in a prokaryotic cell, what is the cell wall composed of
composed of peptidoglycan, more complex than eukaryotic cells
what is the function of the cell wall in prokaryotic cells
o helps maintain cell shape
o protects the cell from osmotic lysis
what is the form DNA takes in a prokaryotic cell
o no membrane-bound nucleus,
o genetic material (DNA) resides in region of nucleoid
o single, circular, double-stranded DNA
what is the function of DNA within a prokaryotic cell
contains essential genes required for survival
what is the structure of the plasmid
small, circular, double-stranded extrachromosomal DNA
what is the function of the plasmid
contains beneficial genes which confer protective traits (e.g. antibiotic resistance, toxin synthesis and enzyme production)
what are the protective traits of a prokaryotic cell
antibiotic resistance
toxin synthesis
enzyme production
what are the purpose of cells
specialised for a particular function
what is tissue
group of cells with similar structures which work together to perform a specific function
what is simple tissue
Simple tissue: a group of cells of the same kind
what are examples of simple tissue
e.g. muscular tissue, epithelial tissue
what is complex tissue
Complex tissue: contains more than one type of cells
what are examples of complex tissue
blood consists of red blood cells, white blood cells, platelets and plasma
what is an organ
contains more than one type of tissue, all working together for a specific function (e.g. stomach)
what is an organ system
consists of several organs working together for a common purpose (e.g. digestive system)
what are the inner foldings of the mitochondria known as
cristae
how is ATP formed
from the oxidation of food substances via aerobic respiration
how are food substances oxidised by the mitochonrdia
aerobic respiration
