Biology Chapter 4 Flashcards
first described a cell in 1665
Robert Hooke
He was the first to describe living cells; discovered bacteria, protists, bloods cells and sperm cells
Antoine van Leeuwenhoek
What are 3 things all cells share?
plasma membrane, nucleus, cytoplasm
Developed the 1st modern cell theory in 1838
Matthias Schleiden
What are the 3 principles of the modern cell theory?
- Cells are the smallest living things; they are the basic unit of organization in all organisms
- All organisms are composed of one or more cells, metabolism and heredity occur within these cells.
- cells arise only by the division of previously existing cells, basically this means the life only started once
Why are cells microscopic?
Cells are able to synthesize quicker when they are small through diffusion, and cells can easily communicate when they are small.
When expanding the radius of a cell, which component expands faster and greater?
Volume
These are the most primitive type of cells, lacking a membrane bound nucleus and membrane bound organelles
prokaryotes
Prokaryotic cell walls are made of this cross linked complexes of carbohydrates and proteins
peptidoglycans
True or False. Archaebacteria have peptidoglycans in their cell wall.
False
network of tubes and fibers that supports cell and anchors the organelles, a scaffolding for the cell
cytoskeleton
found in plant cells, made of cellulose thick impermeable walls
cell walls
The ___ stores DNA which directs all cell biochemistry and has the blueprints for making more cells.
Nucleus
In the center of the nucleus is the __, where there is a lot of synthesis of ribosomal RNA (rRNA)
Nucleolus
2 lipid bilayers surrounding the nucleus
nuclear envelope
The area where the 2 lipid bilayers in the nucleus fuse to form a small hole
nuclear pore
Describe the molecular channels in the nucleus.
There are only 2 kinds of molecules that are allowed passage to and from the nuclear pore.
1- proteins moving into the nucleus to be incorporated with nuclear structures
2- RNA and RNA proteins moving out of the nucleus into the cytoplasm
What is the shape of DNA in eukaryotic cells?
linear
What is the shape of DNA in prokaryotic cells?
ring
When DNA is found in linear structures in the cell
chromosome
When chromosome extend out into very thin threads, allowing access to all DNA material
chromatin
specialized packaging proteins used when a cell wants to divide- the DNA is packaged up into H shape structures
histones
The DNA winds around the histones to form ___ when trying to divide a cell
nucleosomes
the interior of a eukaryotic cell is filled with small membranes
endomembrane system
the largest endomembrane; composed of a lipid bilayer embedded with proteins; forms several folds
endoplasmic reticulum (ER)
one of the endomembrane system organelles found in the cytoplasm; get its name from the large number of ribosomes studded on its surface; proteins are synthesized in this organelle
Rough Endoplasmic Reticulum (rough ER)
is a ribosome that is not attached to a ER; will start protein synthesis by the signal sequence’s queue and will fuse to the ER and finish protein synthesis on the rough ER surface
free ribosome
has a smooth appearance, a lipid bilayer embedded with enzymes, which are responsible for lipid and carbohydrate synthesis
smooth ER
a series of flattened sacs located around the cell (not attached to the roughER)
Golgi apparatus
What is the main function of the Golgi apparatus?
to collect, package and distribute molecules inside and outside of the cell
Transport vesicles bud off of the smooth ER and fuse with the __ face of the Golgi.
cis
Which direction does the cis face?
inward
the last few layers of the Golgi apparatus; where the proteins/carbohydrates/lipids travel through
cisternae
the outward facing side of the Golgi, where the contents of the vesicle is pushed out of
trans face
vesicles that come from the Golgi, but aren’t secreted out of the cell; packed with digestive enzymes and are used to break down macromolecules and organelles
lysosomes
List the 2 types of Lysosomes.
1 - primary, which do not have a low pH and are not functioning
2- secondary, lysosomes that has fused w/something, have a low pH, and are actively digesting something
is when a cell engulfs another cell
Phagocytosis
microbody in plant cells that contain enzymes that convert fats into carbohydrates
glyoxysomes
micro body that contains oxidizing enzymes that are dangerous to the cells metabolism; a bi product of these oxidation enzymes is hydrogen peroxide, which is very toxic to cells (it is broken down in these)
peroxisomes
complex of several strands of ribosomal RNA (rRNA) and several proteins; used to build proteins (where the assembly of amino acids occur)
ribosomes
Where are the ribosomal subunits made in a cell? and where are they assembled
nucleolus; outside the nucleus
process of reading the nucleotide sequence and making the corresponding proteins
translation
power house organelle in the cell; makes the energy the cell needs to fuel its biochemistry; has their own DNA
mitochondria
In regards to making ATP, the ___ takes place in the matrix of a mitochondrion, and the ___ takes place on the cristae.
Kreb’s cycle; electron transport chain
Mitochondria rely on the ___ for replication and ___ live outside the cell.
nucleus; cannot
Chloroplast contain this green pigment that is used to convert the energy from sunlight to energy for the cell
chlorophyll
How many membranes does a chloroplast have? What are stroma, grana and thylakoids?
2 (inner and outer);
stroma- semi fluid matrix surrounding the grana
grana- compartments of stacks of membranes
thylakoids- are the stacks of membranes; the flatten sacks
True or False. Chloroplast do not have their own DNA
false
Where do light reactions and dark reactions occur?
light- thylakoid membrane
dark- stroma
What is the cytoskeleton made of?
microtubules- made up of alpha and beta tubulin (globular proteins); used for moving molecules in the cell (like a track)
actin filaments- made up globular proteins; used for cell movements
intermediate filaments- the toughest; used for structure
