Week 3: Cells Flashcards
True or false: Cells are highly varied and highly organized structures.
True
True or false: The forms and functions of cells are independent on the genetic expression by each cell type.
False. Cells are dependent on the genetic expression.
2 types of cells?
- Somatic
- Gametic
These cells are also called body cells. They constitute the majority of cells in the body.
Somatic cells
Examples of somatic cells?
bone, blood, nerve and muscle cells
Number of chromosomes for somatic cells?
46 chromosomes (diploid) because they have 2 copies of the genome
Number of chromosomes for gametic cells?
23 chromosomes (haploid) because they only have 1 copy of the genome
Examples of gametic cells?
sperm and egg cells
Prokaryotes lack _____ as opposed to the cells of the eukaryotes.
nucleus
True or false: Specialized organelles are present in prokaryotic cells.
False. They are only present in eukaryotic cells.
Major groups of macromolecules in cells?
carbohydrates, lipids, proteins and nucleic acids
Macromolecule that provides energy.
Carbohydrate
In prokaryotes, carbohydrate is found in the?
plasma membrane
In eukaryotes, carbohydrate is found in the?
mitochondria
Function of lipids?
- form membranes and hormones
- provide insulation
- store energy
Functions of proteins in the body?
- important in blood clotting
- nerve transmission
- muscle contraction
- immunity
- serve as catalysts
Most important in genetics are the nucleic acids?
DNA and RNA
All cells are surrounded by a _________, a covering that defines cell boundary.
plasma membrane
It actively controls the movement of materials in and out of the cell.
plasma membrane
They are threads of DNA when the cell is not dividing.
Chromatins
The chromatins will condense which allows proteins to enter, producing?
Chromosomes
The site of rRNA synthesis within the cell. It is present inside the nucleus.
Nucleolus
The site of protein synthesis within the cell, guided by the information contained in the mRNA.
Ribosome
These are paired complex structures located in a specialized region called centrosomes. They produce, organize, and assemble spindle fibers for mitosis and meiosis.
Centrioles
Most animals have _____ or _____ which provides biochemical identity at the surface of cells.
glycocalyx or cell coat
The _____ is a membrane bound structure that houses the DNA, which is complex with protein into thin fibers.
nucleus
Chromatins are _____ and _____ during the nondivisional phases of the cell cycle.
uncoiled and dispersed
During mitosis and meiosis, chromatin fibers coil and condense into?
Chromosomes
In prokaryotes, the genetic material is compacted into an unenclosed region called the?
nucleoid
True or false: The DNA in prokaryotes is not associated with proteins as is the case with eukaryotes.
True
The remainder of the cell within the plasma membrane, excluding the nucleus, is called as the ________ and includes a variety of organelles.
cytoplasm
The ___________ appears smooth in places where it serves as site for synthesis of fatty acids and phospholipids, and in other places, appears rough as it is studded with ribosomes.
endoplasmic reticulum
The endoplasmic reticulum appears smooth in places where it serves as site for synthesis of _____________, and in other places, appears rough as it is studded with _________.
fatty acids and phospholipids; ribosomes
The ________ provide energy by breaking down nutrients from food.
mitochondria
The energy liberated from food is captured and stored in the bonds present in a molecule called?
adenosine triphosphate (ATP)
The organization of spindle fibers by the centrioles plays an important role in the __________ during cell division.
movement of chromosomes
The _______ is a meshwork of protein rods and tubules that molds the distinctive structures of a cell, positioning organelles and providing three-dimensional shape.
cytoskeleton
The cytoskeleton includes three major types of elements?
microtubules, microfilaments, and intermediate filaments
The cytoskeleton is distinguished by?
- protein type
- diameter
- how they aggregate into larger structures
They are long and hollow and provide many cellular movements.
Microtubules
Microtubules are composed of a pair of protein called?
tubulin
Microtubules form the ____, which are hair-like structures.
cilia
These are long, thin rods composed of many molecules.
Microfilaments
Microfilaments are composed of many molecules of the protein _______.
actin
Solid and narrower than microtubules, they enable cells to withstand stretching and compression. They also help anchor one cell to another.
Microfilaments
They have diameters intermediate between those of microtubules and microfilaments.
Intermediate filaments
Intermediate filaments are abundant in?
skin and nerve cells
In actively dividing skin cells, it forms a strong inner framework that firmly attaches cells to each other and to the underlying tissue.
Intermediate filaments
