Chapter 1: Cells Flashcards
Binary fission
One cell divides into two cells, chromosome is copied then each copy move to opposite ends, plasma membrane pinches in Center, two daughter cells are identical, can happen every 20 minutes in ideal conditions
Nuclear pore
It allows communication between the nucleus and the rest of the cell
Pili
Hair like growths on the outside of the cell wall. They are used for attachment.
It’s main function is joining bacterial cells in preparation for the transfer of DNA from one cell to another (sexual reproduction)
The nucleoid region
The nucleoid region contains a single, continuous, circular thread of DNA
What two main categories can cells be divided into?
Prokaryotes (no nucleus) and eukaryotes (nucleus)
Capsule
Outer layer of complex sugars, not always visible
Cell wall
Outer protection maintain the shape of cell
Plasma membrane
Controls what goes in and out of the cell
Flagellum
Long whip-like structures use for mobility (swimming)
Ribosomes
Used for protein synthesis
Cytoplasm
Liquid inside (mostly water) in which all the contents of the cell are found
Characteristics of eukaryotes
Compartmentalization – different zones do separate tasks, this is accomplished by membrane-bound organelles
Organelles
A discrete structure within a cell with a specific function
Endoplasmic reticulum
A network of tubes and flattened sacks used for transportation of materials
Rough ER
– Production of proteins
– transport of these proteins (Often enzymes)
Has ribosomes
Smooth ER
– Production of membrane phospholipids and cellular lipids
– sex hormones
– detoxification of drugs and liver cells – storage of calcium ions in muscle cells
-transportation of lipid-based compounds
– helps the liver release glucose it into the bloodstream when needed
Lysosomes
They are intracellular digestive centers, produced by the Golgi apparatus, contains digestive enzymes
Golgi apparatus
Collection, packaging, modification, distribution of materials made
- The cis (front) side receive the raw materials in vesicles from the ER
- The trans side discharges vesicles and lysosomes with modified materials
Mitochondria
Organelles that produce usable cellular energy
-inner membrane is folded into cristae which pass through the matrix
Nucleus
It contains DNA, bound by double membrane (nuclear envelope or nuclear membrane). It’s function is to isolate chromosomes and make molecules used to build ribosomes. It controls cell division. Some exceptions: Red blood cells have no nucleus or some liver cells that have many nuclei
Chloroplasts
It’s function is photosynthesis (making food from light)
Grana
Piles of thylakoids
Thylakoids
Flattened sacks in charge of collecting light
Stroma
Liquid inside chloroplasts
Centrosome
A pair of centrioles. It assembles microtubules which are useful for cell structure and moving things around
Vacuoles
Membrane-bound storage organelles within the cytoplasm of a cell. They contain water, food, waste, toxins.
Phospholipid bilayer
The two layers of phospholipids are arranged in such a way that their hydrophobic tails are projecting inwards while their polar head groups are projecting on the outside surfaces
Phospholipids and their properties
– Have a head which is polar and therefore hydrophilic
– It contains a phosphate group
– Have two tails of which are non-polar and therefore hydrophobic
– They are made up of fatty acid hydrocarbon chains
Diffusion
The passage of substances from an Area of high concentration to an area of low concentration
Functions of proteins in and on the membrane
– There are peripheral proteins on the surface and integral proteins inside the membrane. Also we can find transmembrane proteins which cut right through it. – Channels for passive transport – enzymatic action – sites for hormone-binding – cell adhesion -cell-to-cell communication -pumps for active transport
What is the source of energy for diffusion?
Kinetic energy
What happens in the diffusion
The particles bump into each other and into the solvent they are dissolved in
Osmosis
The passage of water molecules from an area of low solute concentration to an area of high solute concentration through a semi permeable membrane
What kind of transport is diffusion
Passive transport. No channel needed, no ATP used
What is another kind of passive transport?
Facilitated the fusion, special channel but no ATP
Active transport
Special protein pump and ATP needed
ATP
Helps the protein pumps push the solute against the natural tendency towards equilibrium
Glycoproteins
Composed of carbohydrate chains attached to peripheral proteins.
Stimulus
A change in the internal or external environment that is detected by receptor and causes a response
Allele
One specific form of a gene
Gene
A heritable factor that controls the specific characteristic
Epithelial cells
Any one of several cells arranged in one or more layers that form part of the covering or lining of the body surface
Phospholipids
Make up the cell membrane are hydrophilic as well as hydrophobic
Centrioles
Associated with nuclear division. Composed of microtubules.
Nutrition (as a function of life)
Providing a source of compounds with many chemical bonds which can be broken down to provide the organism with energy and nutrients necessary to maintain life
Paramecium
A Uni cellular member of the kingdom known as Protista
Homeo status (as a function of life)
Caning a constant internal environment (temperature, acid-base levels…)
Facilitated diffusion
Particular type of diffusion involving a membrane with specific carrier proteins that are capable of combining with the substance to aid it’s movement. The carrier protein changes shape to accomplish the task but does not require energy.
List the functions of life
Metabolism Growth Reproduction Response Homeostasis Nutrition (excretion)
Cholesterol
Helps to regulate membrane fluidity and is important for membrane stability
Integral proteins
They completely penetrate the lipid bilayer. They control the entry and removal of specific molecules from the cell
Pluripotent (embryonic) stem cells
These stem cells retain the ability to form any type of cell and an organism
Genome
The whole of the genetic information of an organism
Reproduction (as a function of life)
Involves hereditary molecules that can be passed on to offspring
Cell
Structural, functional and biological unit of all organisms
Nucleolus
A dense, solid structure involved in ribosome synthesis
Meristematic tissue
Occur near root and stem tips of plants and are composed of rapidly reproducing cells that produce new cells capable of becoming various types of tissues within that root or stem
Peripheral proteins
They do not protrude into the middle hydrophobic region, but remain bound to the surface of the membrane
Growth (as a function of life)
Getting bigger, maybe limited but always evident
Cell differentiation
In a multicellular organism, a single cell has the ability to reproduce very quickly. The resulting cells go through a differentiation process to produce all the required cell types that are necessary for the well-being of the organism
Chlorella
A single celled organism
Locus
The location of a gene on a chromosome
Peptidoglycan
A polymer consisting of sugars and amino acids that forms a mesh-like layer outside the plasma membrane of bacteria, forming the cell wall
Metabolism (as a function of life)
All the chemical reactions that occur within an organism
Response (as a function of life)
Responding to the environment, crucial to the survival
Stem cells
Cells that retain the capacity to divide and have the ability to differentiate along different pathways
Lipids
A group of organic molecules that are insoluble in water but soluble and nonpolar organic solvents
Enzymes
Globular proteins which act as catalysts of chemical reactions
Exocytosis
A process by which the contents of the cell vacuole are released to the exterior through fusion of the vacuole membrane with the cell membrane
Endocytosis
Process that allows larger molecules to move across the plasma membrane. It occurs when a portion of the plasma membrane is pinched off.
Phosphorylation
Causes the protein to change shape, thus expelling sodium ions to the exterior
Active transport
Involves the movement of substances against a concentration gradient. It requires energy
Passive transport
Does not require energy. Occurs in situations where there are areas of different concentrations of a particular substance. Movement of a substance occurs from an area of higher concentration to an area of lower concentration
Concentration gradient
A gradual change in the concentration of solutes in a solution as a function of distance through a solution
What is the Endosymbiotic theory?
2 billion years ago a bacterial cell took up residence inside a eukaryotic cell, they formed a symbiotic relationship, the bacterial cell went through a series of changes to ultimately become a mitochondrion
Interphase
Largest phase of the cell cycle, major event is growth of the cell, replication of the DNA, chromosomes. Prepares for mitosis, DNA begins to condense from chromatin two chromosomes and microtubules may begin to form
Cyclins
Group of proteins that control the cells progression through the cell cycle
Mitosis
The replicated chromosomes separate and move to opposite poles of the cell, the S providing the same genetic material at each of these locations. Then the cytoplasm divides, to form two daughter cells.
Supercoiling
The DNA first wraps around histones to produce nucleosomes. The nucleus zones are for the wrapped into a solenoid. Solenoids group together and looped domains to produce the chromosome
Solenoids
The super coiled arrangement of DNA and eukaryotic nuclear chromosomes produced by coiling the continuous string of nucleosomes
Nucleosomes
Any of the repeating subunits of chromatin occurring at intervals along the strand of DNA consisting of DNA coiled around histones.
Histones
Proteins the DNA tightly coils around to form chromosomes
Centromere
The constricted region joining the two sister chromatids that make up the X-shaped chromosome
Chromatid
Either of the two strands joined together by a single centromere, formed by the duplication of the chromosomes during the early stages of cell division and then separate to become individual chromosomes
Four phases of mitosis
Prophase, metaphase, anaphase, telophase
Mitotic spindle
The collective term for all the spindle fibers that form during mitosis. It is a spindle shape structure that develops outside the nucleus during mitosis. The fibers that constitute the mitotic spindle pull the chromatids apart toward opposite poles
Kinetochore
Large multi protein complexes that bind the centromeres of the chromosomes to the microtubules of the mitotic spindle during metaphase.
Microtubules
A hollow cylindrical structure in the cytoplasm of most cells involved in intracellular shape and transport
Cytokinesis
Once nuclear division has occurred, the cell undergoes cytokinesis. In animal cells, it involves an inward pinching of the fluid plasma membrane to form cleavage furrows. Plant cells with a firm cell wall form a cell plate. It occurs midway between the two poles of the cell. Two separate daughter cells are created that have genetically identical nuclei.
Metastasis
The transfer of disease from one organ or part to another not directly connected with it.
Oncogenes
The gene the causes the transformation of normal cells in the cancerous tumor cells.
Mutagen
An agent that can induce or increase the frequency of mutation in an organism
Histones
Proteins the DNA tightly coils around the form chromosomes
Centromere
The constricted region joining the two sister chromatids that make up the X-shaped chromosome
Chromatid
Either of the two strands joined together by a single centromere, formed by the duplication of the chromosomes during the early stages of cell division and then separate to become individual chromosomes
Four phases of mitosis
Prophase, metaphase, anaphase, telophase
Mitotic spindle
The collective term for all the spindle fibers that form during mitosis. It is a spindle shape structure that develops outside the nucleus during mitosis. The fibers that constitute the mitotic spindle pull the chromatids apart toward opposite poles
Kinetochore
Large multi protein complexes that bind the centromeres of the chromosomes to the microtubules of the mitotic spindle during metaphase.
Microtubules
A hollow cylindrical structure in the cytoplasm of most cells involved in intracellular shape and transport
Cytokinesis
Once nuclear division has occurred, the cell undergoes cytokinesis. In animal cells, it involves an inward pinching of the fluid plasma membrane to form cleavage furrows. Plant cells with a firm cell wall form a cell plate. It occurs midway between the two poles of the cell. Two separate daughter cells are created that have genetically identical nuclei
Metastasis
The transfer of disease from one organ or part to another not directly connected with it.
Oncogenes
The gene the causes the transformation of normal cells in the cancerous tumor cells.
Mutagen
An agent that can induce or increase the frequency of mutation in an organism
Histones
Proteins the DNA tightly coils around the form chromosomes
Centromere
The constricted region joining the two sister chromatids that make up the X-shaped chromosome
Chromatid
Either of the two strands joined together by a single centromere, formed by the duplication of the chromosomes during the early stages of cell division and then separate to become individual chromosomes
Four phases of mitosis
Prophase, metaphase, anaphase, telophase
Mitotic spindle
The collective term for all the spindle fibers that form during mitosis. It is a spindle shape structure that develops outside the nucleus during mitosis. The fibers that constitute the mitotic spindle pull the chromatids apart toward opposite poles
Kinetochore
Large multi protein complexes that bind the centromeres of the chromosomes to the microtubules of the mitotic spindle during metaphase.
Microtubules
A hollow cylindrical structure in the cytoplasm of most cells involved in intracellular shape and transport
Cytokinesis
Once nuclear division has occurred, the cell undergoes cytokinesis. In animal cells, it involves an inward pinching of the fluid plasma membrane to form cleavage furrows. Plant cells with a firm cell wall form a cell plate. It occurs midway between the two poles of the cell. Two separate daughter cells are created that have genetically identical nuclei
Metastasis
The transfer of disease from one organ or part to another not directly connected with it.
Oncogenes
The gene the causes the transformation of normal cells in the cancerous tumor cells.
Mutagen
An agent that can induce or increase the frequency of mutation in an organism
Histones
Proteins the DNA tightly coils around the form chromosomes
Centromere
The constricted region joining the two sister chromatids that make up the X-shaped chromosome
Chromatid
Either of the two strands joined together by a single centromere, formed by the duplication of the chromosomes during the early stages of cell division and then separate to become individual chromosomes
Four phases of mitosis
Prophase, metaphase, anaphase, telophase
Mitotic spindle
The collective term for all the spindle fibers that form during mitosis. It is a spindle shape structure that develops outside the nucleus during mitosis. The fibers that constitute the mitotic spindle pull the chromatids apart toward opposite poles
Kinetochore
Large multi protein complexes that bind the centromeres of the chromosomes to the microtubules of the mitotic spindle during metaphase.
Microtubules
A hollow cylindrical structure in the cytoplasm of most cells involved in intracellular shape and transport
Cytokinesis
Once nuclear division has occurred, the cell undergoes cytokinesis. In animal cells, it involves an inward pinching of the fluid plasma membrane to form cleavage furrows. Plant cells with a firm cell wall form a cell plate. It occurs midway between the two poles of the cell. Two separate daughter cells are created that have genetically identical nuclei
Metastasis
The transfer of disease from one organ or part to another not directly connected with it.
Oncogenes
The gene the causes the transformation of normal cells in the cancerous tumor cells.
Mutagen
An agent that can induce or increase the frequency of mutation in an organism
Histones
Proteins the DNA tightly coils around the form chromosomes
Centromere
The constricted region joining the two sister chromatids that make up the X-shaped chromosome
Chromatid
Either of the two strands joined together by a single centromere, formed by the duplication of the chromosomes during the early stages of cell division and then separate to become individual chromosomes
Four phases of mitosis
Prophase, metaphase, anaphase, telophase
Mitotic spindle
The collective term for all the spindle fibers that form during mitosis. It is a spindle shape structure that develops outside the nucleus during mitosis. The fibers that constitute the mitotic spindle pull the chromatids apart toward opposite poles
Kinetochore
Large multi protein complexes that bind the centromeres of the chromosomes to the microtubules of the mitotic spindle during metaphase.
Microtubules
A hollow cylindrical structure in the cytoplasm of most cells involved in intracellular shape and transport
Cytokinesis
Once nuclear division has occurred, the cell undergoes cytokinesis. In animal cells, it involves an inward pinching of the fluid plasma membrane to form cleavage furrows. Plant cells with a firm cell wall form a cell plate. It occurs midway between the two poles of the cell. Two separate daughter cells are created that have genetically identical nuclei
Metastasis
The transfer of disease from one organ or part to another not directly connected with it.
Oncogenes
The gene the causes the transformation of normal cells in the cancerous tumor cells.
Mutagen
An agent that can induce or increase the frequency of mutation in an organism
Extracellular Matrix (ECM)
In many animal cells, composed of collagen fibres + sugars and proteins called glycoproteins, creating fibre-like structures that anchor the matrix to the plasma membrane. This strengthens the plasma membrane and allows attachment between adjacent cells. It allows cell-to-cell interactions.
Chlorella
a single-celled organism that has one very large structure called chloroplast inside a cell wall. This structure enables the conversion of sunlight to a chemical energy called carbohydrate.
Carbohydrate
any of a class of organic compounds composed of carbon, hydrogen, and oxygen, including starches and sugars, produced in green plants by photosynthesis: important source of food for animals and people.
Prokaryotic Cells Characteristics
- DNA not enclosed within a membrane (forms one circular chromosome)
- DNA is free, not attached to proteins
- lack membrane-bound organelles
- their cell wall is made up of a compound called peptidoglycan
- -divide by binary fission
- small in size, between 1 and 10 micrometers
- only in bacteria
- no compartmentalization
Organelles of Eukaryotic cells
- endoplasmic reticulum
- ribosomes
- lysosomes
- golgi apparatus
- mitochondria
- nucleus
- chloroplasts
- centrosomes
- vacuoles
Plasmids
A segment of DNA independent of the chromosomes and capable of replication, occurring in bacteria and yeast
What do plant cells have in the membranes to maintain proper membrane fluidity? (cholesterol in animal cells)
saturated and unsaturated fatty acids
Proteins as sites for hormone binding
specific shapes exposed to the exterior that fit the shape of specific hormones. the attachment between the hormone and the protein causes a change in the shape of protein, results in a message being relayed to the interior of the cell
Proteins for enzymatic action
cells have enzymes attached to membranes that catalyze many chemical reactions. The enzymes may be on the interior or exterior of the cell.
Proteins for cell adhesion
proteins that can hook together in various ways to provide permanent or temporary connections.
Proteins for cell-to-cell communication
proteins have carbohydrate molecules attached to it. They provide an identification label that represents the cells of different types of species.
Proteins as channels in passive transport
provides passageways for substances to be transported through. When this transport is passive, material moves through the channel from an area of high concentration to an area of low concentration
Proteins as channels in active transport
proteins shuttle the substance from one side of the membrane to another by changing shape. This process requires the expenditure of energy in the form of ATP.
Hypertonic solution
a hypertonic solution is one with a higher concentration of solutes outside the cell than inside the cell. When a cell is immersed into a hypertonic solution, the tendency is for water to flow out of the cell in order to balance the concentration of the solutes.
Hypotonic solution
opposite of hypertonic solution: lower concentration of solutes outside the cell than inside the cell. When a cell is immersed into a hypotonic solution, the tendency is for water to stay in the cell. Water moves from a hypotonic solution to a hypertonic solution.
Isotonic solution
An isotonic solution refers to two solutions having the same osmotic pressure across a semipermeable membrane. This state allows for the free movement of water across the membrane without changing the concentration of solutes on either side of the membrane.
the 2 factors that determine whether the substance can easily move across a membrane
Size and charge. Small and non-polar molecules cross easily such as gases (oxygen, carbon dioxide and nitrogen) and water and glycerol. Big and polar molecules have difficulty such as ions (chloride ions, potassium ions, sodium ions and glucose and sucrose)
The sodium-potassium pump
the mechanism for actively moving sodium and potassium ions
Cell theory
- all organisms are composed of one or more cells
- cells are the smallest units of life
- all cells come from the pre-existing cells
What experiment did Louis Pasteur disprove?
Spontaneous Generation
S phase
replication of the DNA of the cell (chromosomes). The synthesis phase
G1 phase
growth of the cell, cellular contents apart from chromosomes are duplicated
G2 phase
the cell grows and makes preparations for mitosis. Organelles may increase in number, DNA begins to condense from chromatin to chromosomes and microtubules may begin to form
