Cells

Question 1

Robert Hoooke

Answer 1

Described cambers in corks and named them cells

Question 2

Anton Van Leeuwenhoek

Answer 2

Saw animalcules in pond cells and described them as LIVING cells

Question 3

Mathias Scheindein

Answer 3

Stated all plant tissue is composed of cells

Question 4

Theodor Swann

Answer 4

Stated that cells are the structural unit of cells. As well as describing plant and animal tissue being composed of cells

Question 5

Rudolf Virchow

Answer 5

Stated that cells can arise only by division from an existing cell

Question 6

Basic Properties of Life

Answer 6

Highly complicated/ organized, posses a genetic program and the means to use it, capable of producing more of themselves, acquire and utilize energy, mechanical activities, capable of self- regulation, sensitive to stimuli

Question 7

Prokaryotes

Answer 7

Nucleoid, no membrane bound organelles, single - naked chromosomes, reproduce via binary fission, no cytoskeleton, little DNA for fewer proteins

Question 8

Eukaryotes

Answer 8

Membrane bound organelles, Membrane bound nucleus, numerous chromosomes, reproduce via mitosis/ meiosis, cytoskeleton, much more DNA for protiens

Question 9

Types of prokaryotes

Answer 9

Archeabacter:
Methanogens: converts CO2+H2 –> CH4
Halophiles: live in salty environments
Thermoacidphiles: live in acidic hot springs

Eubacteria:
Mycoplasma: smallest living cell (lack a cell wall)
Cyanobacteria: photosynthetic releasing O2

Question 10

Types of Eukaryotes

Answer 10

Unicellularity:
Protozoans- most complex single cell- organisms; do everything as an individual organism

Multicellularity:
Human, animal, fruit fly- cell differentiation and specification for various functions

Question 11

Both Prokaryotes and Eukaryotes

Answer 11

Identical genetic language: DNA
Common set of metabolic pathways: respiration
Some structural features: plasma membrane

Question 12

Why are cells so small? How do larger cells get around this problem?

Answer 12

Cells are so small for the diffusion efficiency and the surface area/ volume ratio. Large cells like the Ostrich egg or the Giraffe nerve cell get around these problems by:
Ostrich egg- very little protoplasm spread over the top and lots of inert yolk nutrients
Giraffe nerve cell- very long but very small diameter

Question 13

Plasma membrane

Answer 13

The fluid mosaic model states that the core lipid bilayer exists in a fluid state, capable of dynamic movement, membrane proteins form a mosaic of particles. Some of these proteins are internal proteins others are peripheral proteins associated with the inner/ outer membrane

Membrane Composition:
Lipids, proteins, carbohydrates

Membrane functions:
compartmentalization: organelles, selective permeability (selective barrier) regulate the exchange of substance across the membrane, responding to external signals; receptors in membranes, transporting solutes like ions O2, CO2.

Question 14

Nucleus

Answer 14

The Nucleus is the most reliable feature distinguishing prokaryotes and eukaryotes.

Nuclear Envelope:
A prominent structure of the cell, visible under a light microscope. It is a complex structure used to store genetic materials.

Question 15

Chromosomes

Answer 15

Clearly visible ONLY during cell division, composed of DNA and proteins in eukaryotic cells.

Question 16

Endoplasmic Reticulum (ER)

Answer 16

The ER is an irregular maze of spaces enclosed by membranes.
Rough ER- coated in ribosomes, location for protein synthesis
Smooth ER- lacks ribosomes, location for lipid synthesis

Question 17

Golgi Apparatus

Answer 17

Stack of flattened membrane- bound sacs, takes the products from the Rough ER packages, tags, modifies, and ships them either around the cell or outside of the cell (exocytosis)

Question 18

Lysosomes

Answer 18

Small and irregular shaped, digest particles to release nutrients/ break down unwanted molecules for excretion/ recycling

Question 19

Cholorplasts (in plant cells)

Answer 19

Double membrane, the outer membrane is permeable to large molecules, inner membrane is folded into flattened sacs (thylakoids); produces chlorophyll (the green pigment in plants), Contains small DNA molecules

Origin of Chloroplasts:
symbiosis- ancient eukaryotic cells engulfed bacteria

Question 20

Peroxisome

Answer 20

Small, membrane- bound vesicles which provide a contained environment for reactions by which dangerous chemical can be generated/ degraded (hydrogen peroxide)

Question 21

Cytoskeleton

Answer 21

Types:
Actin filament, microfilament, intermediate filament

Functions:
Structural support, internal framework to position organelles in cell interior, separation of chromosomes during cell division, movement of materials in cell interior

Question 22

Cytosol

Answer 22

Water based gel containing various molecules
membrane + organelles = cytosol

Question 23

mitochondrion

Answer 23

Bacteria sized; sausage shaped; outer and inner mitochondrial membrane; matrix DNA, ribosomes, and enzymes, a limited amount of RNA and proteins can be synthesized in the matrix; Binary fission.

Origin of mitochondrion:
Bacteria engulfed by an ancient eukaryotic cell

Aerobic Respiration: provide energy for cellular activities: Adenosine Triphosphate (ATP)