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