2 - Basic components of living things Flashcards
Name the two main types of organism
Prokaryotes (a single-celled organism that lacks a nucleus and other membrane-bound organelles) & Eukaryotes (organisms whose cells contain a nucleus and other membrane-bound organelles.)
Define Organelles
Membrane bound compartment within the cell each providing distinct environments and therefore conditions for different cellular reactions
Features of an ANIMAL cell under a LIGHT microscope
Cell Surface Membrane
Cytoplasm
Nucleus
Mitochondria
Centriole
Cytoplasmic Granules
Features of a PLANT cell under a LIGHT microscope
Cell Wall
Cell surface membrane
Cytoplasm
Nucleus
Vacuole
Tonoplast
Mitochondria
Starch grains
Chloroplast
Features of an ANIMAL cell under an ELECTRON microscope
Cell Surface membrane
Rough endoplasmic Reticulum (RER)
Nucleolus
Nucleus
Smooth Endoplasmic Reticulum (SER)
lysosome
Ribosome
Nuclear envelope with pores
Golgi apparatus
Cytoplasm
Mitochondria
Features of a PLANT cell under an ELECTRON microscope
Cell Surface membrane
Chloroplast
Rough endoplasmic Reticulum (RER)
Plasmodesmata
Nucleolus
Nucleus
Smooth Endoplasmic Reticulum (SER)
Ribosome
Nuclear envelope with pores
Golgi apparatus
Cytoplasm
Mitochondria
Vacuole
Cell Wall
Function of cell-surface membrane
A thin, selectively permeable protein and phospholipid bilayer that controls the movement of materials in and out of the cell, which also has receptor molecules to allow it to respond to chemicals.
Function of a plant cell wall
A tough yet elastic wall of cellulose that surrounds and supports the cell wall. It is freely permeable. Defence mechanism against invading pathogens.
Function of the nucleus
Comprised of nuclear envelope with nuclear pores, nucleoplasm, nucleolus and DNA molecules . DNA molecules which control the cell’s activities; they associate with histone molecules to form chromatin. Chromatin coils tightly to form chromosomes. The pores in the nuclear envelope allow substances such as RNA to move between the nucleus and cytoplasm. Nucleolus is an area within the nucleus that makes ribosomes.
Function of a lysosome
A round organelle surrounded by a membrane, with no clear internal structure that contains digestive enzymes that are kept separate from the cytoplasm by the membrane. these enzymes enable the lysosome to digest invading cells or break down worn out components of the cell.
Function of a Ribosome
Small organelle that either floats free in the cytoplasm or is attached to the RER, where proteins are made during protein synthesis.
Function of (RER) Rough Endoplasmic Reticulum
A system of membranes enclosing a fluid filled space, the membrane surface is covered with ribosomes, folds and processes proteins made by the ribosomes packaging them into vesicles.
Function of (SER) Smooth Endoplasmic Reticulum
A system of membranes enclosing a fluid filled space, synthesizes and processes lipids
Function of a Vesicle
A small fluid filled sac in the cytoplasm surrounded by a membrane, transports substances in and out of the cell, via the cell surface membrane, and between organelles.
Function of Golgi Apparatus
A group of flat fluid filled sacs, sometimes seen with vesicles at the edge. Processes and packages new lipids and proteins, also makes lysosomes.
Function of mitochondria
Usually oval-shaped, with a double membrane. The inner membrane is highly folded to form cristae. The fluid inside the cristae is called the matrix. The membrane forming the cristae contains enzymes used in aerobic respiration. Also contain mitochondrial DNA, produce their own enzymes and can reproduce themselves.
Function of Chloroplast
Small Flattened structure in plant cells, has a double membrane enclosing a thick fluid called stroma. They also have an internal network of membranes called thylakoid membranes, which form flatten sac called thylakoids. Several thylakoids are stacked to form granum. Grana are linked by thin pieces of thylakoid membrane called lamellae. The grana contain the chlorophyll pigments where the light-dependent reactions occur during photosynthesis.
Function of centriole
Component of the cytoskeleton present in most eukaryotic cells. Small hollow cylinders containing microtubules. Two associated centrioles form the centrosome, which is involved in the assembly and organisation of the spindle fibres, and therefore the splitting chromosomes during cell division.
Structure = sets of three microtubules with one in the center.
Function of Cilia
Small hair-like structures found on the surface membrane of some animal cells. Cross section appears like a wheel with an outer membrane and nine pairs of microtubules arranged in a ring around two pairs in the center. Microtubules allow the cilia to move which is used to move substances along the cell surface e.g. In the trachea to sweep dust and dirt out of the lungs.
Function of Flagella
Long hair-like Structures that stick out from the cell surface and are surrounded by the plasma membrane. Cross section appears like a wheel with an outer membrane and nine pairs of microtubules arranged in a ring around two pairs in the center. Microtubules contract to make flagellum move, this is used to propel cells forward e.g. the tail of a sperm cell, this requires energy.
Proteins are made…(where?)
Mainly at the ribosomes attached to the RER. These proteins are stored in the RER until they can be processed and packaged at the golgi apparatus. Some ribosomes are free in the cytoplasm and the proteins they produce also stay in the cytoplasm.
In the RER proteins are..
folded and processed, being modified in ways such as having sugar chains added.
Proteins are transported from the RER to the…
Golgi apparatus in vesicles.
At the Golgi apparatus the proteins…
undergo further processing where sugar chains are trimmed or more are added.
Proteins are transported in/out/around cells in…
vesicles
Secretory cells, which release hormones or enzymes, have more…
rough endoplasmic reticulum than cells that do not release proteins.
Proteins may be stored…(in which organelle?)
in the rough endoplasmic reticulum until they are needed by the Golgi apparatus
The cytoskeleton is made of which three components:
- Microfilaments - contractile fibers formed from the protein actin.
- Microtubules - globular tubulin proteins polymerized to form tubes that act as a scaffold structure determining the shape of a cell. Also act as tracks for the movements of organelles.
- Intermediate fiber - fibers that give mechanical strength to cells and help maintain their integrity.
Microtubules, microfilaments, intermediate fibers
MT - form scaffold like structures that determines the shape of the cell. also acts as tracks to organelles. spindle fibers are made outta mt
MF - responsible to cell movement and cell contractions - made outta actin
IF - give mechanical strength to the cells
Vacuole
Membrane lined sac in plant cells containing cell sap. Large permanent vacuoles as used to maintain turgor. The membrane of the vacuole is called the tonoplast. It is selectively permeable. if vacuoles appear in animal cells they are small and transient.
Prokaryotic vs. eukaryotic - cell size
Prokaryotic - extremely small, less than 2 µm diameter
Eukaryotic - Larger Cells, 2-200 µm diameter
Prokaryotic vs. eukaryotic - Nucleus & DNA
Prokaryotic - No nucleus, DNA free in cytoplasm, DNA is circular, organised by proteins folding and condensing DNA.
Eukaryotic - Nucleus Present, DNA inside nucleus in form of chromosomes, DNA is Linear. Organized by DNA molecules associating with histones to form chromatin, which is condensed to form chromosomes.
Prokaryotic vs. eukaryotic - Extra chromosomal DNA
Prokaryotic - found in plasmids
Eukaryotic - found in chloroplasts and mitochondria
Prokaryotic vs. eukaryotic - Organelles
Prokaryotic - non-membrane bound
Eukaryotic - both non-membrane bound and membrane bound
Prokaryotic vs. eukaryotic - Ribosomes
Prokaryotic - smaller, 70S
Eukaryotic - larger, 80S
Prokaryotic vs. eukaryotic - Cystoskeleton
Prokaryotic - present but basic
Eukaryotic - present, more complex (microfilaments, microtubules, & intermediate fibres)
Prokaryotic vs. eukaryotic - Reproduction
Prokaryotic - binary fission
Eukaryotic - asexual or sexual
Prokaryotic vs. eukaryotic - Cell type
Prokaryotic - unicellular
Eukaryotic - unicellular or multicellular
Prokaryotic vs. eukaryotic - Cell membrane
Present in both
name the 4 sample prep techniques
dry mount
wet mount
squash slides
smear slides
equation for magnification
magnification = image/real
the two types of electron microscopes and the cool stuff they do
transmission electron microscope (TEM) - 2D image, higher resolution/magnification.
scanning electron microscope (SEM) - 3D image, lower resolution/magnification
what is resolution?
the ability to distinguish two points within an image
