Chapter 4 Flashcards
Cell biology
Definition
What people in this field aim to do
The study of individual cells and their interactions with eachother. People in this field want to learn about cells and apply that knowledge to treating diseases like cancer and cystic fibrosis
Cell theory
Credited to with contributions from
Has 3 parts
Schleiden and schwann with contributions from Virchow
1. All living organisms are composed of one or more cells 2. Cells are the smallest unit of life 3. Times new cells come from pre existing cells by division
Microscope
Magnification tool that allows researches to see the structure and inner workings of cells
Micrograph
An image taken with the aid of a microscope
Robert Hooke
In 1655 studied cork under a compound microscope and observed cell walls and coined the word cell ( from cellula meaning small compartment)
Resolution
Measures clarity of an image. Microscope with good resolution allows a researcher to distinguish two adjacent chromosomes as two different objects
Magnification
And an example of it
Ratio between size of the image produced by the microscope and its actual size.
Exp if the image size is 100 times larger than its actual size, the magnification is 100x
Light microscope
Electron microscope
Who invented electron
Microscope that uses light for illumination
Uses a bean of electrons for illumination. Invented by max knoll and Ernst risks
Cell structure is determined by 4 factors
- Matter- is made of atoms molecules and macromolecules
- Energy- needed to produce molecules and macromolecules
- Organization- molecules and macromolecules are found at specific sites
- Information- cell structure needs instructions these are found in DNA
Genome
The complete genetic composition of a cell or species. Every species has a distinct genome and every cell has a copy of the genome
Genes
Found in the genome, genes contain the information to produce certain proteins with particular structures and functions. Those proteins in turn are mostly responsible for determining that cells structure and function
Prokaryotic cell
Definition
Examples
Have a simple structure and lack a membrane enclosed nucleus.
Bacteria and archaea both have prokaryotic cells and they’re both small( I micrometer-10micrometers in diameter)archaea are less common and usually found in extreme temps like hot springs and deep sea vents
Some bacteria are pathenogenic and cause disease
Plasma membrane
A double layer of phospholipids and embedded proteins provide a barrier between the cell and the external environment
Cytoplasm
The part of the cell contained inside the plasma membrane. The cells nucleoid resides there, the place where genetic material is kept in prokaryotic cells
Ribosomes
What they do what they look like
Involved in poly peptide synthesis
Cell wall
Definition/ purpose
Description
What it’s made of
Nearly all bacteria and archaea have a rigid cell wall that supports and protects the plasma membrane and cytoplasm.
it is porous allowing nutrients to reach the plasma membrane
usually made of peptides and carbs
Glycocalyx
A thick sticky material that sor rounds the outer bacteria body. It helps trap water so the bacteria doesn’t dry out
Capsule
A very thick gelatinous glycocalyx that some bacteria produce when they enter animal and human bodies to help them avoid being killed by immune systems and helps them attach to cell surfaces. A
Pili
Tiny hairs on the outside of bacteria that helps them attach to cells
Flagella
Tail like hairs that help prokaryotic cells move( aka gives them motility)
Eukaryotes
All organisms besides bacteria and archaea including fungi plant animals and protists
Protists
Single called organisms like algae and paramecium
Organelle
A membrane bound compartment with its own unique structure and function.
Nucleus
An organelle found in eukaryotes that stores most of the DNA
Compartmentalizations
Eukaryotes have many membrane bound organelles that speedster the cell into many regions. This allows a cell to do special chemical reactions in different places
Structures found in plant cells but not animal cells
There’s 3
- Chloroplast- site of photosynthesis
- central vacuole- watery area that provides storage and regulates cell volume
- cell wall- provides the cell with support
A cells characteristics are largely determined by
The proteins that cell makes
Multicellular
Plants and animals are both multicellular, it means they’re made up of many cells
Proteome
The entire set of proteins expressed by a genome, cell, tissue or organism at any given time
Most genes…
Give instructions for the production of polypeptides- which end up assembling into functional proteins
What is largely responsible for determining the characteristics of a cell
The set of proteins it makes
Two cells can have identical genes but very different structure and organization and protein composition
4 reasons why
- proteins found in one cell may not be produced in a different cell.
- They might produce the same proteins but in different amounts ( due to gene regulation and rate of synthesization and degradation.)
- Amino acid sequences of particular proteins may vary ( due to SPLICING!)
- Different cells alter their proteins in different ways( for example covalent bonding)
What is largely responsible for traits such as eye color?
Disease
Proteomes
Proteome change and disease are linked; the proteomes of a healthy and a cancerous lung are different
Why are most cells small
They rely on plasma membrane to import nutrients and export waste. The rate of transport is limited by the membranes surface area. As the radius of the cell gets bigger, the surface area to volume ratio gets smaller
Cytosol
The watery area inside the plasma membrane where the organelles reside.
Metabolism
The reactions that allow cells to utilize the energy necessary to sustain life
Cytosol is a central coordinating region for many metabolic activities
The metabolic pathway
A number of steps involved in metabolism. Each step is catalyzes by a specific enzyme
Enzyme
A protein that accelerates the rate of a chemical reaction
Catabolism
And the pathway related to it
The breaking down of molecules into smaller components. This happens in one pathway of the metabolic process. The pathways where this happens are needed to utilize energy and to generate molecules that will provide building blocks to make macro molecules
Anabolism
And exp of it
The synthesis of molecules and macromolecules
For example polysaccharides are made by linking sugars
Cytoskeleton is a network of 3 types of protein filaments: #1 Description/ what it's made of Interesting thing it can do Where it's located in animal cells And protists and plant cells
- Microtubules- long hollow cylinder structures made of protein subunits called X and B Tubulin. They can switch from growing and shortening phases(dynamic instability) in non dividing animal cells the microtubule area is near the nucleus and it’s called the CENTROSOME(which has centrioles in it) most plant cells and protists don’t have this so instead microtubules are made at many sites throughout the cell.
Cytoskeleton is a network of 3 types of protein filaments: #2
Intermediate filaments. Maintain cell shape and rigidity. Smaller than microtubules. They bind to eachother In a staggered way that makes a twisted rope structure. Their size is permament, the other two can grow or shrink
Cytoskeleton is a network of 3 types of protein filaments: #3
Actin filaments aka microfilms to. Dispersed through Cytosol but tend to be near plasma membrane
