Module 1 Flashcards
State cell theory
Every living organism is made up of cells ,and substances produced by cells
Cells are the basic structural and functional units of all living things
All cells come from pre-existing cells
Identify features of cells
Plasma membrane
Cytoplasm
Nucleic acid, often enclosed in its own membrane
Organelles
Varying degrees of specialisation, depending on structures they possess
The ability to divide in two
Outline metabolism
The sum of the chemical reactions - the making and breaking of molecules - that take place in a cell
Outline the importance of chemical substances
Make up the structures that we can see under a microscope and the number of combination of the structures that determine what a cell can do
State the function of the plasma membrane
Holds cells together and regulate what goes in and out
Identify the two factors that govern the size of cells
The need to exchange material with the cell’s external environment - nutrients needed to taken in and waste needs to be removed
The need to move nutrients, wastes and cell products around the interior
State what occurs on the outer surface of a cell
Site of gas exchange with the external environment
State what occurs on the inside of the cell
Metabolic functions occur
Describe the relationship between cell size and SA:V
As the size of a cell increases, it’s surface area to volume ration decreases. The bigger the cell, the smaller it’s surface area is in relation to its volume
Outline the importance of increasing the SA:V
By increasing the area of these surfaces, greater numbers of molecules can be transported at one one time
Describe why carbon based molecules are able to serve a number of functions in living organisms
A carbon atom has 4 valence electrons (electrons on the outer energy level) and therefore can make 4 bonds with itself or with other elements
Define monomer
A small piece of a polymer - building block
Define polymer
A large molecule made up of several repeating units
Outline the directionality of polymers
When monomers are stacked together there will be directionality- depending on the direction monomers are being added, the structure and function of biological molecules will differ
Identify the elements in carbohydrates
Carbon, hydrogen and oxygen
State the function of carbohydrates
To act as a quick source of energy for the body
State the function of carbohydrates
To act as a quick source of energy for the body
Identify the monomer of carbohydrates
Monosaccharide
Identify the polymer of carbohydrates
Polysaccharide
Identify the structure of carbohydrates
Ring
Identify the elements in proteins
Carbon, hydrogen, oxygen and nitrogen
Outline the function of proteins
Proteins are used in enzymes, hormones, antibodies & the as part of the basic building blocks of life
Identify protein monomer
Amino acids
Identify the polymer of proteins
Polypeptides
Identify the shape of protein
Folded amino acid chain
Describe the function of the variable side chain in amino acids
Variable R group differentiates amino acids from other amino acids and gives important characteristics in the structure of a protein by having chemical, characteristics differences
Identify the elements in nucleic acids
Carbon, hydrogen, oxygen and phosphorus
Outline the function of nucleic acids
To store and transmit genetic information through generations
State the location of nucleic acids
Most,y found within the nucleus of eukaryotic cells or floating within prokaryotes
Identify nucleic acid monomer
Nucleotide
Identify nucleotide polymer
Nucleic acids
Describe the structure of nucleotide monomer
Phosphate group attached to a 5’ carbon sugar, attached to a nitrogenous base
Identify nucleotide nitrogenous bases
Cytosine, guanine, adenine and uracil (RNA) or thymine (DNA)
State the nucleic acid shape
Double (DNA) or single (RNA) helix
State the directionality of nucleic acids
RNA travels from one direction to the other
DNA travels in an antiparallel direction
Identify the elements in lipids
Carbon, hydrogen and oxygen
Outline the function of lipids
Make up cell membranes and store energy
Describe the structure of lipids
Glycerol head attached to a fatty acid tail
Identify the polarity of the glycerol head in lipids
Hydrophilic and polar - attracted to water
Identify the polarity of the fatty acid tail in lipids
Hydrophobic and non polar - repels water
Define somatic cell
Any cell in the body of an organism, except sex cells (eg. sperm and egg cells)
Define cell cycle
The sequence of cell growth and division
Identify the phases of the cell cycle
Interphase - G1, S and G2 phase
Cell Division - Mitosis and Cytokinesis
Describe G1 phase of interphase
A cell is busying growing and carrying out whatever function it is suppose to do - some cells will exit the cell cycle after G1 because they don’t divide again
Describe S phase of interphase
After a cell grows to the point where it is no longer able to function well and needs to divide, it will enter the S phase where a copy of the DNA will be made
Describe G2 phase of interphase
Once DNA replication is complete he cell will enter the shortest interphase, the G2 phase undergo further preparations for cell division
Outline the product of cell division
At the end of the M phase, there will be 2 daughter cells identical to each other and the original (parent) cell
Outline similarities between prokaryotic and eukaryotic cells
Contain a cell membrane composed of phospholipid and proteins
Use DNA as the basis of their genes
Cytosol acts as the site of metabolic processes
Ribosomes
Outline structures of eukaryotic cells
Double membrane bound nucleus w/ DNA
Contain other complex, large membrane bound organelles
Between 10 to 100 microns (typically)
Mostly, but not entirely, multicellular organisms
Big, complex membrane bound ribosomes
Reproduce sexually
DNA forms tightly bound and organised chromosomes
State the function of the plasma membrane
Provides a barrier between the external and internal environments and selectively allows certain materials to pass through
State the function of DNA
Contains the genetic material regulates cell function and coded material to pass on to the offspring
State the function of cytosol
Act as the site of metabolic processes
Outline the structure of prokaryotic cells
DNA is found in the nucleoid
Typically between 1 to 10 microns
Always unicellular
Contains a single loop of stable chromosomal DNA stored in the nucleiod
Smaller, simple,Ed ribosomes compared to eukaryotic ribosomes
Large SA:V resulting in higher metabolic rate and increased growth
Define cytoplasm according to eukaryotic cells
Everything in the cell outside the nucleus
Define cytoplasm according to prokaryotic cells
Everything contained inside the cell membrane
Outline the reason for variety of functions in a cell
Organelles determine the functions of a cell, and therefore the variation in the number and type of organelles contributes to the variety of functions that exist within a cell
Identify the common features between cells
Cell/plasma membrane that separates the inside of the cell for its outside
Cytosol
Genetic material at some time during their life
Structures and chemical reactions that produce proteins
Identify the two major groups of cells
Prokaryotes and eukaryotes
Describe the importance of cytochrome C in grouping cells
Cytochrome C is a protein composed of 100 amino acids which is involved in the respiration of glucose, and therefore found in most living things - the more closely related two organisms are, the more similar their cytochrome C molecules
Identify the 3 kingdoms organisms are grouped as
Eucarya, bacteria and archaea
State the features of eucarya
Living things with a membrane bound nucleus- all living things without bacteria and archaea
State the features of bacteria
Living things found in environments with moderate temperatures which are rich in organic nutrients and have high levels of sunlight
State the features of archaea
Living things found in environments with extremely high temperatures and high concentrations of salt or acid
Define species
If organisms are able to interbreed to produce viable, fertile offspring
Describe how the evolutionary tree changes and evolves
When a population mates at random, that population will remain one species even though there might be some structural and functional changes. However, some evolutionary changes may isolate some members of a population to a point where the members can no longer reproduce
State the consequence/s of prions, viroids and viruses
They are much smaller than the wavelength of visible light,meaning they are not invisible under the light microscope and solutions of them in water are not cloudy
Describe the structures and features of prions
Consists of a protein molecule without nucleic acid
Describe the structures and features of viroids
Particles that are smaller than viruses and comprise only a circular strand if RNA. They do not have a protein coat and are found only in plant cells
Describe the structure and features of viruses
Consist of genetic material that holds the genes of the virus, surrounded by a protein coat or envelope. They don’t have a cellular structure and can’t function outside living cells. Additionally, they use the host cell’s organic compounds, enzymes and organelles to reproduce
Describe the structure and features of virions
Purified and dried viruses that form crystals
Identify types of prokaryotic cells
Bacteria and other single celled organisms
State features of prokaryotic cells
All:
External cell membrane
Genetic material free in the cytoplasm
Ribosomes for the production of protein
May have:
Cell wall
Structures for movements (eg, flagellate, cilia)
Identify feature/s absence in prokaryotes
Organelles bound by a membrane
Outline the distinguishing feature of eukaryotes
They have cellular organelles that are covered with a membrane similar to the cell membrane
Identify eukaryotes
Animals, plants, fungi and protists
Identify features of eukaryotic celsls
All:
Double cell membrane
Cytoplasm
Internal’scaffold’ for support or plasticity
Membrane bound organelles
Distinct membrane-bound nucleus
Some:
Cell wall
Structures for movement
Identify ways organelles can be seen
High powered light microscope or electron microscope
Describe the nucleus
Usually the largest organelle in the cell
Site if DNA replication and genetic control of the cell’s activities
Contains the nucleolus
Surrounded by two membranes that form the nuclear envelope
Describe the nucleolus
Contains ribosomal RNA and therefore creates ribosomes
Describe ribosomes
Found free in the cytoplasm or bound to the ER, or in the chloroplast and mitochondria
Site of protein synthesis
Describe the endoplasmic reticulum
Two types - smooth and rough
Network of interconnecting membranes distributed throughout the cytoplasm
Lumen, internal compartment, contains a distinct protein and ion composition
Folding generates surface area greater than the plasma membrane
Describe the rough endoplasmic reticulum
Has ribosomes attached that actively synthesise proteins destined for the ER interior or incorporation into the membrane of the ER
Describe the smooth endoplasmic reticulum
Region free from ribosomes
Within the lumen, some proteins synthesised on the RER are modified
Site for the synthesis and hydrolysis of glycogen in liver cells
Site for the synthesis of lipids and steroids
Describe the Golgi apparatus
Consists of cisterns and membrane bound vesicles
Receives and modifies proteins from the ER
Concentrates and packages proteins before they are sent off to their final destination
Describe lysosomes
Organelles that come in part from the Golgi
Creates primary lysosomes, vesicles containing digestive enzymes
Primary lysosomes fuse with phagosomes to create secondary lysosomes
Within the secondary lysine’s, the digestive enzymes hydrolyse macromolecules into monomers
Remaining undigested materials is expelled when the secondary lysine’s fuses with the plasma membrane
Describe the mitochondria
Converts the potential energy of fuel molecules into a form the cell can use (ATP) in cellular respiration
Contain an outer lipid I layer and highly folded inner membrane
Mitochondrial matrix in the inner matrix containing enzymes and DNA to make protein’s
Small amount
Crustal has embedded proteins
Folding gives greater surface area, resulting it faster chemical reactions
Describe perioxisimes
Small organelles that are specialised to compartmentalise toxic peroxides, the by products of cellular chemical reactions, and break them down
Describe the cell membrane
Double layer of phospholipids
Hydrophobic hidden tails
Hydrophilic exposed head
Acts as a protective barrier to the uncontrolled flow of water
Describe the centrosome
Where microtubules are produced
Centrosome divides during cell division, creating 2 centrosome s
From each centrosome, microtubules grow into a spindle fibre which is respiration for seperating replicated chromosomes
Describe the centrioles
Found in animal cells only
Each is a ring of nine Garoua’s of fused microtubules
Arranged such that one is perpendicular to the other
Describe the secretory vesicles
Cell secretions are packaged at the Golgi body and then transported to the cell surface for release
Describe the vacuole
Membrane bound sac that plays a role in intracellular digestion and the release of cellular waste products
Small in animal cells but large in plant cells
Stores nutrients and waste products, helping increase cell size during growth
Regulates turf or pressure in plant cells
Describe the cytoskeleton
Comprised of a set of long, thin fibres found in the cytoplasm
Supports the cell and maintains its shape; provides for cell movement; positions organelles within the cell; acts as a track for motor proteins that help move materials within cells; interacts with extra cellular structures
Three types - microfilaments, intermediate filaments and microtubules
Outline the relationship between cell specialisation and organelles
The shape of a cell and the number and type of organelles it contains are closely related to the major function of a cell
eg. High metabolic rate requires a large number of mitochondria for ATP production
Outline how cells control inputs and outputs
An individual cell cannot control the temper of its external environment and has little control on its internal environment, however it can control all the chemical substances needed to take to excrete substances
Membrane surrounds each cell and acts as a primary regulator for taking in and excreting substances
Describe the cell membrane structure
Plasma membrane has a phospholipid bilayer, while the 3D structure depends on the properties of the molecules involved
Hydrophobic head that dissolves in water with a hydrophobic double tail, and therefore will rearrange itself to point the fat-soluble tails point away from water
State what holds the phospholipid bilayer together
By the pressure of the water of the cytoplasm on one side and the extra cellular fluid on the other
Outline the distribution of membrane proteins
All biological membranes contain proteins, either embedded in the phospholipid bilayer or extend across it. However many proteins have both polar and non polar regions due to the presence of both hydrophilic and hydrophobic groups in the amino acids
Identify the bonds between membrane carbohydrates and lipids or proteins
Covalent bonds
Outline the function of proteins on the plasma membrane
Control transport through membrane hormone receptors
Outline the function of carbohydrate chains on the membrane
Aid in cell recognition for inter-cell communication and defence again disease-causing agents
Outline the function and structure of glycolipid molecules
Attached directly to hydrophilic head
Involved in cell-cell recognition
Outline the function and structure of large glycoproteins
Extend through the membrane
Provide pathways for the movement/transport of ions and smaller molecules in and out of the cell
Describe integral proteins
Cross the entire phospholipid bilayer
Describe cholesterol molecules in the membrane
Interspersed among phospholipid tails, influencing the fluidity of fatty acids in the membrane
Identify molecules that can move through the membrane
Oxygen, carbon dioxide, water, urea and ethanol
Identify molecules that can’t pass through the membrane
K+, Na+, Cl-, HCO3-, H2PO4-, glucose, sucrose
Describe the influence of charge on the ability of substances to move through the membrane
Substances that move into or out of a cell must be soluble in water, because the cell contents and its external environment are water-based
The membrane controls the movement of substances, and molecules that are too large cannot move through the cell membrane
Describe the process of Endocytosis
A depression forms in the cell membrane, new phospholipid molecules are needed for this to extend the cell membrane
Substance fills the developing depression until it is enclosed in a vesicles
Phospholipid molecules rearrange themselves to join over the neck, enclosing the substance in a bubble
When the bubble breaks, the molecules within it are free in the cytoplasm of the cell
Outline phagocytosis
Large particles can be engulfed by the plasma membrane
Outline pinocytosis
Small dissolved particles and fluids are bight into the cell
Outline the benefits of exocytosis
Large molecules manufactured in a cell are released to the cells external environment, protecting the cell’s interior from the consequences of potentially destructive substances causing damage within the cytoplasm
Describe how molecules move through the membrane
Atoms and molecules are constantly moving - shuttling back and forth at temperatures above absolute zero - and bouncing off each other to move in random directions
State the direction of passive transport
Move down the concentration gradient from high to low areas of concentration
Describe facilitated diffusion
Particles move from high to low concentration and the processes does not require energy. However, the path that the particles take is through carrier and channel proteins embedded in the lipid bilayer of the cell membrane
Describe carrier proteins
Wrap the substrate, changing shape and flipping the molecule to the other side of the membrane
Describe channel proteins
When the gates are open, solutes pass through; when the gates close, the passage of the solute is blocked
Outline the benefits of facilitated diffusion
Faster than simple diffuse, and it provides with a greater concentration of the substance than can occur by simple diffusion. It is very selective because each particular embedded protein can provide a pathway only for a specific substance
Define osmosis
Movement of water molecules across a semi-permeable membrane
Outline a hypotonic solution
Salt concentration below that of a standard solution,
Outline an isotonic solution
Salt concentration equal to that of a standard solution
Outline a hypertonic solution
Solutions that have a salt concentration higher than that of a standard solution
Describe the importance of IV drips
IV drips allow for a constant level of the medicine to be maintained in the blood, as most drips are made to be isotonic to blood. If they were not, blood cells would lose water (solution is hypertonic) or gain water (solution is hypotonic)
State the direction of active transport
Move against the concentration gradient from low to high areas of concentration
Describe pump proteins
Required in active transport - extend through the membrane and are able to change shape to carry a molecule or ion through the me
Describe transport proteins
Move around the lipid bilayer as part of the fluid matrix - substance to be transported is able to fit into a space at one end of the protein molecule and the transported particle is carried along its length and deposited on the opposite side of the membrane
Outline receptor mediated Endocytosis
When specific molecules are carried into the cell
State the process of receptor mediated Endocytosis
Molecules to be transported first bind to specific receptors on the plasma membrane
The interior portion of the receptor protein is embedded in the membrane
Protein clathrin coats the inside of the membrane in the area of the pit
When an appropriate collection of more,clues gather in the coated area of the pit, the pit deepens and seals off to form a coated vesicles that Carrie’s molecules into the cell
Identify types of Endocytosis
Phagocytosis, pinocytosis, receptor mediated Endocytosis
Identify types of active transport
Endocytosis & exocytosis
Identify types of passive transport
Simple diffusion, facilitated diffusion and osmosis
Identify the needs of all cells
Internal and external environment that contains sufficient water
Temperatures that stay within a narrow range
Adequate supply of nutrients
Correct balance of salts and pH in the internal and external environment
Means of removing wastes and toxic substances
