cell structure and taxonomy (pt.1)

Cell

The basic unit of structure and function in living things

Metabolism

All of the chemical reactions that occur within an organism

Procaryotic Cells

Cells without true nuclei, lacking many other structures found in eucaryotic cells.

- archaea and bacteria

Eucaryotic Cells

cells possessing a nuclear membrane and other membrane-bound organelles

What is the result of reverse evolution?

Viruses

Viruses

they are composed of a few genes protected a protein lining

why is it important for the health professionals to know the cell structures?

so that they can identify each of their metabolic functions

Cytology

study of structure and function of cells

difference about size and diameter of eukaryotes and prokaryotes

eukaryotes are bigger in size and is 10-30 mm diameter

Cell Membrane

A cell structure that controls which substances can enter or leave the cell.

Three components of a nucleus

nucleoplasm, chromosomes, and a nuclear membrane

Nucleoplasm

semi-solid fluid inside the nucleus that contains the chromatin and nucleolus

Chromosomes

threadlike structures made of DNA molecules that contain the genes

Nuclear Membrane

controls what goes in and out of the nucleus

Eucaryotic Chromosomes consists of a

they consist of a linear DNA molecules and proteins

where are genes located?

DNA

Gene products

this is when the genes that contains genetic information produces more genes

two types of ribonucleic acid where genes codes for their reproduction

- ribosomal ribonucleic acid and tRNA

Genotype

genetic makeup of an organism

estimation of the human genome

20,000-30,000 genes

how is the nucleolus seen?

through the Transmission Electron Microscope

Where is rRNA made?

nucleolus

where is most of the cell metabolic reactions occur?

cytoplasm

Cytosol

Fluid portion of cytoplasm

Endoplasmic Reticulum

A cell structure that forms a maze of passageways in which proteins and other materials are carried from one part of the cell to another.

Rough ER

ER that is dotted with ribosomes

Smooth Endoplasmic Reticulum

An endomembrane system where lipids are synthesized, calcium levels are regulated, and toxic substances are broken down.

Eucaryotic Ribosomes

- they consist mostly of RRNA and proteij wnr plqy importanr role of protien synthesis

What are sometimes observed by electron microscopy

polyribosomes in contact with messenger rNA

each eukaryotic ribosomes consists of two subunits

large 60S, small 40S

what is the S in the S in the subunits of ribosomes?

Svedberg units

Sedimentation coefficient

A measure of the rate of movement due to centrifugal force

what happens when 40 S and 60 S meets

they form 80S

Golgi Complex

organelle that modifies, packages, and transports material out of the cell.

Lysosomes

An organelle containing digestive enzymes

Autolysis

self-destruction of cells; decomposition of all tissues by enzymes of their own formation without microbial assistance

Lysosomes location

cytoplasm

Peroxisomes

it contains catalase that fastens the break down of hydrogen peroxide into wayer and oxygen

Location of most peroxisomes

mamallian livers

Mitochondria

Powerhouse of the cell, organelle that is the site of ATP (energy) production

Plastids

A group of membrane‐bound organelles commonly found in photosynthetic organisms and mainly responsible for the synthesis and storage of food.

Chloroplast

An organelle found in plant and algae cells where photosynthesis occurs.

pigment: chlorophyll

chloroplasts are found where

algae and plant cells

Photosynthesis

Conversion of light energy from the sun into oxyen and carbohydrates.

Cytoskeleton

A network of fibers that holds the cell together, helps the cell to keep its shape, and aids in movement

Microtubules

Spiral strands of protein molecules that form a tubelike structure (tubulin)

3 types of cytoskeleton fibers

1) microtubules

2) microfilaments

3) intermediate fibers

Cell Walls

A rigid layer of organic material surrounding delicate cell membranes of bacteria

Eukaryotic Cell Walls

made of cellulose or chitin d it consists of other things

Cell walls of an algae

cellulose

What can be found in the cell wall of plants

cellulose

what is found in the cell wall of a fungi?

chitin

Mycoplasma

bacteria that lack cell wall

Types of cells where cell walls are absent

- Mycoplasma

- Animals

- Protozoa

Cells that has a cell wall

- most bacteria, algae, plants, and fungi

Flagella

A long, whip-like filament that helps in cell motility. Many bacteria are flagellated, and sperm are flagellated. for locomotion.

Cillia

hair like projections of a cell that move in wave like motion.

shorter and thinner than flagella, but more numerous

Prokaryotic Cell Structure

- 10 times smaller than eukaryotic cells

- Simpler than eukaryotic cells

- Reproduce by binary fission

- All bacteria are prokaryotes, as are archaea

- Unlike eukaryotic cells, the cytoplasm of prokaryotic cells is not filled with internal membranes

- The cytoplasm of prokaryotic cells is surrounded by a cell membrane, a cell wall (usually), and sometimes a capsule or slime layer

binarry fission

The division of bacteria cells into two new cells called daughter cells.

separation of cell membrane and cell wall

what is embedded within the cytoplasm of procaryotes?

chromosomes, cytoplasmic molecules

Cell Membrane (prokaryotes)

- frequently observed in TEMS

- has enzymes where metabolic reactions takes place

- no organelles

Inward foldings of cell membranes in prokaryotes

mesosomes where the cellular reactions takes place

Procaryotic Chromosome

- usually consists of a single, long, supercoiled, circular DNA molecule and serves as the control center of the cell

- it is capable of duplicating itself guiding cell division

Bacterial Nucleoid

contains the bacterial chromosome within the area of the cell

Size of Escherichia coli and its chromosome

2 to 3 mm

1.5 to 2nm

how many bacteria chromosomes contain

between 450 to 8k genes

extrachromosomal DNA/ Plasmids

small circular double stranded dna that are not part of the chromosome but may be present in the cytoplasm

Bacterial Cells and Plasmids

bacterial cells may contain no plasmids, or one plasmid, or many copies of the same

Plasmids have also been found where?

yeast

Cytoplasm (prokaryotes)

-

Most tiny particles observed in the cytoplasm of prokaryotes

ribosomes

difference between prokaryotic ribosomes and eukaryotic

it is smaller but same function

how many ribosomes are in the cytoplasm of E.Coli

15k

Cytoplasmic Granules

- these can be defined, depending on what species of bacteria it can be stained by a stain and can be identified microscopically.

- These granules may contain starch, lipid, sulfur, iron, or other stored substances.