Bio Test #6 Flashcards
Where do eukaryotic cells occur?
Eukaryotic cells occur in algae, protozoa, fungi, plants, & animals
What are characteristics of Eukaryotic cells?
Euk. cells can be unicellular or multicellular, from 5 micrometers to 100 micrometers
How are eukaryotic cells characterized?
They are characterized by nucleus & organelles
What are the 2 types of Endoplasmic Reticulum?
Smooth ER & Rough ER
What is the structure of smooth ER?
has a network of tubules & vesicles around the nucleus (sometimes continuous with the nucleus); membrane bound organelle
What are functions of Smooth ER?
synthesis of lipids, breaks down carbohydrate, detoxify from drugs, regulates calcium concentration in the cell, produces sex hormones
What is the structure of Rough ER?
has a network of tubules & vesicles (sometimes continuous with nuclear membrane); membrane bound organelle; studded with ribosomes (gibing it a rough appearance)
What are the functions of Rough ER?
synthesis of protein that are needed on the cell membrane of the cell; rough ER surrounds protein with a vesicle
What is the structure of Golgi Apparatus?
series of membrane bound stacks called cisterna(ae)
What are the functions of Golgi Apparatus?
works with ER to repackage & transform proteins or lipids & send them to the right destination; vesicles from ER fuse with cisternae, each region of the Golgi contains enzymes that modify the content of the vesicle
What is the structure of mitochondrian?
double membrane organelle; inner membrane folds & increases its surface and forming crista/ae; fluid inside is called matrix & contains ribosomes and genetic material & enzymes
What is the function of mitochondria?
production of ATP
What is the structure of lysosomes?
membrane bound organelle made by Golgi; it contains digestive enzymes
What is the function of Lysosomes?
digest worn out organelles, food, engulfed bacteria or viruses
What is the structure of ribosomes?
non-membrane bound organelles; made of rRNA & proteins & consist of 2 subunits
What is the function of ribosomes?
protein production (protein that remain in the cell)
What is the structure of centroiles?
barrel shaped organelle made of proteins; part of centrosome
What is the function of centroiles?
involved with the organization of mitotic spindle
What is the structure of Nuclear Envelope?
double membrane; has pores; impermeable to most substance
What is the function of Nuclear Envelope?
protect genetic material; regulate what moves in & out of nucleus
What is the structure of DNA?
deoxyribonucleic acid
What is the structure of Chromosomes?
protein & DNA forms chromatin, arranged into a chromosomes
What are the functions of DNA & Chromosomes?
long term storage of info, controls activity of cell, passes genetic info to daughter cell.
What are characteristics of Mitochondrian?
range in size from 1 to 10 micrometers; different cells have different numbers of mitochondria
What is the structure of cell wall?
Its made of cellulose and has 3 layers
Cellulose
arranged into bundles of fibers called microfibrils
What are the functions of the cell wall?
maintains shape of cell, prevents cell from bursting, allows plant to grow against gravity
What are the 3 layers of the cell wall?
Primary Cell wall (outside)
Middle Lamella
Secondary Cell Wall (inside)
What is the structure of Chloroplast?
double membrane organelle
What is the function of chloroplast?
site of photosynthesis
stroma
liquid inside chloroplast and contains ribosomes, enzymes, & DNA loop
What is the structure of Central Vacuole?
liquid filled vacuole containing water, enzymes, waste, toxic substances
What are the functions of Central Vacuole?
storage of water, support, defense
What are differences of animal cells compared to plants?
no cell wall, has glycogen as carb storage, roundish shape (flexible), no chloroplasts, no vacuoles or temporary vacuoles, has cholesterol in cell membrane, has centrioles
What are differences of plant cells compared to animals?
has cell wall, plants have starch as carb storage, rectangular shape (fixed), have chloroplast always has central vacuoles, do not have cholesterol in cell membrane, has no centrioles
cell membrane
a selectively permeable phospholipid bilayer found in all cells
What is the structure of a phospholipid?
has 3 parts: phospho alcohol head, glycerol, fatty acid tail
Which part of phospholipid is hydrophilic?
the polar phospho alcohol head
Which part of a phospholipid is hydrophobic?
the non-polar fatty acid tails
Why do phospholipids tend to arrange into a bilayer that has continuous & spherical shape?
because of the polar head & non-polar tail
Why is the plasma membrane very flexible & can be broken with enough force?
because the tails are just close to each other but do not form bonds
What allows endo & exocitosis?
the plasma membrane’s flexibility
plasma membrane
semi-permeable membrane & can control what goes in & out of the cell
Why do animal cells have cholesterol interspersed between the phospholipids?
It ensures that the membrane can function at a wider range of temperature
Why do plant cells have a mix of saturated & unsaturated fatty acids?
to allow the membrane to function at different temperatures
What are the types of proteins found in cell membrane?
integral, peripheral, glycoproteins
integral
embedded in the phospholipid membrane, can have many functions (transport, enzyme, hormone binding site, cell adhesion)
Peripheral
adheres temporarily to the cell membrane
can attach to integral protein
glycoproteins
protein & carbohydrate tail
important for cell recognition
What can movements of substances be?
passive and active
Passive
without use of energy (ATP)
Active
needs energy to occur (ATP)
What are types of Passive Transports?
Diffusion and Osmosis
diffusion
the passive movement of particles from an area of high concentration to an area of low concentration
What are types of diffusion?
simple (unaided) and facilitated
Why does diffusion occur?
it results from the random motion of particles
high concentration
an area with lots of molecules
low concentration
an area with few molecules
concentration gradient
difference between high and low
What does it mean when molecules move along the concentration gradient?
that molecules move from an area of high concentration to an area of low concentration
What does it mean when molecules move against the concentration gradient?
to move from low concentration to high concentration
What are factors that affect rate of diffusion?
concentration gradient (greater the concentration difference between 2 areas, the greater diffusion)
distance involved
area involved
barrier to diffusion
distance involved
diffusion over a short distance is faster then diffusion over a long distance
area involved
the larger the area, the greater the diffusion
barrier to diffusion
thinner the membrane the faster the diffusion
What are characteristics of simple diffusion?
through membrane, through channel protein, used for small uncharged molecules (cell membrane) or small & charged (channel protein)