Cell Flashcards
Multicellular
many cells
Unicellular
Made of a single cell
Prokaryote
unicellular organism that lacks a nucleus
Eukaryote
organism whose cells contain a nucleus
jobs of cells
make energy, make proteins, make more cells
Glucose + Oxygen
carbon dioxide + water + energy
nucleus
Control center of the cell. Contains DNA.
Nucleolus
Found inside the nucleus and produces ribosomes which move out of pores in the nuclear envelope and latch onto the outside of rough endoplasmic reticulum
Mitochondria
the site of respiration using oxygen
location - muscles, liver, brain cells
Ribosomes
made of two subunits which join together to manufacture proteins
rER
contains many ribosomes and is important in the formation and storage of protein
Golgi apparatus
works together with the rER and is important in storing and packaging molecules such as protein and lipids ready for transport
Lysosomes
contains enzymes whose main role is to digest waste
cilia/flagellum
short hairs like structure that move liquid past the cell surface and help the cell to move
Cytoskeleton
is a flexible, fibrous structure consisting of microtubules, intermediate filaments, and microfilaments. the structure provides a secure scaffolding for the organelles and provides support for whole cells
Centrioles
two hollow cylinders arranged at the right angle of each other they are important in spindle formation during cell diffusion
peroxisome
mall vessels containing oxygenated enzymes. helped remove toxic substances
plasma memebrane
surrounds every cell is sometimes referred to as the cell surface membrane. it controls the passage of substances in and out of the cells.
structure of plasma membrane
is made up of proteins and phospholipids, cholesterol, lipids and carbohydrates
Phospholipids
is a special type of lipid molecule they have two distinct regions a hydrophilic ‘head’ that is attracted to water, and at the end a fatty acid hydrophobic tail that repels water. they provide the structure of the cell surface membrane
cholesterol molecules
help to stabilise the membrane and regulate the fluidity so it does not become too rigid or too fluid
Glycolipids
molecules project out into the solution surrounding the cell and help to stabilise the membrane. they act as receptor molecules
Glycoproteins
identify the cell type
extracellular fluid
fluid outside the cell
interstitial fluid
the fluid inside the cell that supports the cell by proving oxygen and nutrients and it is the recipient for waste products from the cell
diffusion
Movement of molecules from an area of higher concentration to an area of lower concentration.
it doesn’t require energy the random movement of molecules bumping into each other makes enough energy for them to move. the rate of this depends on the concentration on both sides of the cell.
facilitated diffusion
some molecules will not easily pass through the cell membrane by diffusion these molecules cross the membrane by passing through channels created by proteins in the membrane
Osmosis
is the movement of water molecules across a permeable membrane from a region where they occur at a high concentration
Hypotonic
the cell inflates and eventually bursts. water is transported into the cell. solute concentration inside the cell is higher
hypertonic
the cells shrink water is transported out from the cell solute concentration inside the cell is lower
active transport
the movement of dissolved molecules into or out of a cell through the cell membrane, from a region of lower concentration to a region of higher concentration
cytosis
movement of molecules into and out of the cell with vesicles
Endocytosis
movement of substances into the cell
Exocytosis
movement of substances out of the cells
DNA was described by
Watson and Crick in 1953
ribonucleic acid (RNA)
single-stranded nucleic acid that contains the sugar ribose
Mitosis
is the process of cell division seen in all nucleated eukaryotic cells. it occurs during normal development, growth, and healing. it also produces two daughter cells that are identical to each other and to the parent cell.
the daughter cell have the same amount of chromosomes
function of mitosis
repair and replacement of tissues this occurs rapidly in certain tissues for example the skin where cells are constantly dying and being replaced
binary fission
asexual reproduction occurs by mitosis. two daughter cells are produced from one single parent. the offspring produced are identical to the parent cell.
the stages of mitosis are
idiot please make another two cells
interphase, prophase, metaphase, anaphase, telophase, cytokinesis
Interphase (Mitosis)
Before mitosis, the cell must get prepared to divide and get ready to produce an identical sister cell.
During interphase the cell increases in mass and size, producing new proteins, cytoplasm, and organelles and replicating its DNA to produce a duplicate set of chromosomes, all whilst still carrying out normal cellular activities.
As the cell prepares to divide, the chromosomes become denser, thicker, and more visible.
Prophase (mitosis)
The chromosomes coil and condense, appearing as separate strands.
During prophase, the old and new chromosomes are joined at a point in the centre known as the centromere.
The two joined chromosomes are known as chromatids and are identical to each other.
The nucleolus and the nuclear envelope disappear and the centrioles begin moving to the opposite ends (poles) of the nucleus.
Metaphase (mitosis)
The paired chromatids arrange themselves along the equator of the cell.
Microtubule spindles, formed by the centrioles, attach to the centromere.
Anaphase (Mitosis)
The paired chromatids begin to split apart at the centromere - one of each pair is pulled along the strands of the fibrous spindle tubule towards each pole, centromere first.
Telophase/Cytokinesis (Mitosis)
The cell cytoplasm begins to divide into two and the chromatids move into each cell.
The nuclear membrane reforms around each group of chromatids.
The cytoplasm continues to divide until two new identical cells are formed, this process is known as cytokinesis.
smooth endoplasmic
is the production and storage of lipids
fibrous protein
supports shape and form
microfilament
assist with cell movement
intermediate filament
enables the cell to withstand the mechanical stress that occurs when a cell is stretched
microtubules
regulates cell growth and movement
DNA
deoxyribonucleic acid it provides genetics code for amino acids
DNA structure
DNA has a double helix and 4 bases adenine, thymine/ cytosine, and guanine. a and t c and g
these 4 bases form the double helix. the DNA is formed by nucleotides and it carries genetic information
DNA codes for amino acids
the codes of amino acids are formed by the bases as they form structures called a triplet. Each triplet is coded for a particular amino acid. the order of the bases code for an amino acid in the polypeptide chain which makes up protein
phagocytosis
the cell’s plasma membrane surrounds a molecule in the extracellular environment and buds off to form a vacuole that contains the molecule. the molecule is then digested by enzymes
pinocytosis
is the same as phagocytosis excepts the cell’s plasma membrane surrounds droplets of fluid containing dissolved solutes
