Zoo-Lec (Sem-1) - Chapter 1: The Cell

zoology

the study of animals

zoon

Greek for "animal"

logos

Greek for "to study"

1.4 million

amount of described animal species

anatomy

study of structure of an entire organism + parts

cytology

study of structure and function of cells

comparative genomics and bioinformatics

study of the structure, function, and evolution of the genetic composition of groups of animals using computer-based computational methods

ecology

study of interactions between organisms and their environment

embryology

study of the development of an animal from the fertilized egg to birth or hatching

genetics

study of the mechanisms of transmission of traits from parents to offspring

histology

study of tissues

molecular biology

study of subcellular details of structure and function

parasitology

study of animals that live in or on other organisms at the expense of the host

physiology

study of the function of organisms and their parts

systematics

study of classification of biodiversity

entomology

taxonomic category; study of insects

herpetology

taxonomic category; study of amphibians and reptiles

icthyology

taxonomic category; study of fishes

mammalogy

taxonomic category; study of mammals

ornithology

taxonomic category; study of birds

protozoology

taxonomic category; study of protozoa

Robert Hooke (1635-1703)

English polymath; first coined the term "cells"; discovered cells by looking at a thin slice of cork; his discovery led to the development of the classical cell theory

thin slice of cork

the specimen Robert Hooke was observing where he noticed a honeycomb structure that reminded him of cells in monasteries, thus coining the term "cell"

Antonie van Leeuwenhoek (1632-1723)

Dutch microbiologist; Father of Microbiology; created simple microscopes that could magnify over 275 times; discovered bacteria, protists, sperm cells, blood cells, microscopic nematodes, and rotifers (+many more); discovered them by observing pond water using a microscope

Matthias Schleiden (1804-1881)

German botanist; co-founder of the classical cell theory; coined the term "cytoblast"

Theodor Schwann (1810-1882)

German zoologist; co-founder of the classical cell theory; discovered Schwann cells and Pepsin

Rudolf Virchow (1821-1902)

German physician; Father of Pathology; co-founder of the classical cell theory; coined the phrase "omni cellula e cellula"

omni cellula e cellula

phrase coinded by Virchow, meaning "every cell stems from another cell"

classical cell theory

3 theories about cells proposed by Schleiden, Schwann, and Virchow

All organisms are composed of one or more cells

first part of cell theory; proposed by Schleiden and Schwann

The cell is the structural unit of life

second part of cell theory; proposed by Schleiden and Schwann

Cells can arise only by division from a pre-existing cell

third part of cell theory; proposed by Virchow

DNA replication

the process in which DNA makes a duplicate copy of itself.

division

the process by which the contents of a mother cell are distributed into two daughter cells

electromagnetic radiation from the sun

the source of all the energy utilized by life on the Earth's surface

miniaturized chemical plants

cells function like this type of industrial processing plant

enzymes

required by all chemical changes in cells; molecules that speed up chemical reactions

the sum total of the chemical reactions in a cell

represents that cell's metabolism

Krebs cycle

pyruvic acid is broken down into carbon dioxide in a series of energy-extracting reactions

cytoskeletal fiber/cytoskeleton

the fiber on which the motor protein travels on carrying cargo

motor proteins

a class of molecular motors that can move along the cytoskeleton of cells; they convert chemical energy into mechanical work by the hydrolysis of ATP

Adenosine triphosphate (ATP)

the source of energy for use and storage at the cellular level

cell receptors

the main reason behind the cell's response to stimuli; in cell membrane; receive hormones and neurotransmitters

programmed cell death (PCD)

a response to stimuli; death of a cell caused by events within the cell, such as apoptosis

self-regulation

feedback circuits activate to return the cell to an appropriate state after dangerous fluctuations in composition and behavior

mutation

any change in the cell's DNA sequence

evolution

the reason behind the diversity of cells and its different types in the modern day

precellular life form

what cells evolved from; what evolved from nonliving organic materials that were present in the primordial seas

last universal common ancestor (LUCA)

the common ancient ancestral cell with which all organisms evolved from more than three billion years ago

prokaryotic cells

simple-structured cells that do not have a nucleus or other membrane-bound organelles

eukaryotic cells

more complex-structured cell with a nucleus and membrane-bound organelles

bacteria

single-celled organisms that lack a nucleus; prokaryotes

protists, fungi, plants, and animals

4 Kingdoms in Domain Eukarya

cyanobacteria

photosynthetic, oxygen-producing bacteria (formerly known as blue-green algae)

approx. 2.7 billion years ago; surely 2.4 billion years ago

the time when cyanobacteria first appeared; theorized because that is when the atmosphere became infused with molecular oxygen as a by-product of the photosynthetic activity of this prokaryote

600 million years ago

time when complex multicellular organism first appeared on fossil records; substantial evidence that eukaryotes appeared even way before

mitochondria

eukaryotic membrane-bound organelles that transform energy stored in food molecules; has a highly folded inner membrane that produces energy-storing molecules

chloroplast

eukaryotic membrane-bound organelle which is the site of photosynthetic activity

cellulose

carbohydrate component of plant cell walls; eukaryotic function

phagocytosis

process in which extensions of cytoplasm surround and engulf large particles and take them into the cell; eukaryotic function

diploidy

the state of being diploid, that is having two sets of chromosomes; eukaryotic function

RNA polymerases

enzymes that bond nucleotides together in a chain to make a new RNA molecule; eukaryotic function

meiosis

a type of cell division that results in four daughter cells each with half the number of chromosomes of the parent cell, as in the production of gametes and plant spores; eukaryotic function

nucleoid

what a prokaryote has as opposed to the nucleus of eukaryotes; stores the genetic material of prokaryotic cells

before, nucleus

pro, karyon

true, nucleus

eu, karyon

relatively small

amount of DNA in prokaryotic cells

separate chromosomes

eukaryotic chromosome

circular chromosomes

prokaryotic chromosome

simple diffusion

movement of a solute from an area of high concentration to an area of low concentration

devoid of membranous structures

a feature that differentiates prokaryotes and eukaryotes; the inside of a prokaryotic cytoplasm that is opposed to the interconnecting structures of eukaryotic cytoplasm

conjugation

prokaryotic cells are usually asexual, except for...; the passing of DNA from one cell to another

structural complexity

the distinction between eukaryotic and prokaryotic cells, as opposed to phylogenetic relationships

Archaea (Archaebacteria); Bacteria (Eubacteria)

the two major taxonomic groups or domains of prokaryotes

eukaryotes; prokaryotes

members of Archaea are more closely related to ____________ than they are to the other group of _____________

extremophiles

Archaea; thrive in extremely inhospitable environments

methanogens

Archaea that release methane, a greenhouse gas.

halophiles

"salt-loving" archaea that live in environments that have very high salt concentrations

acidophiles

Archaea that grow best in acidic habitats

thermophiles

Archaea that are heat loving microbes

hyperthermophiles

Archaea growing about 80 degrees celcius and some above 100 degrees celcius

mycoplasma

belonging to Domain Bacteria; known as the smallest free living bacteria

nitrogen fixation

a capability of cyanobacteria other than photosynthesis; conversion of nitrogen into reduced forms of nitrogen

roughly 6000

amount of species of prokaryotes that have been identified using traditional techniques

1 to 5 µm

size range of a prokaryotic cell

10 to 30 µm

size range of a eukaryotic cell

fibroblasts

10-15 micrometers in size; produce fibers and ground substance

plasma membrane; cytoplasm/cytosol; DNA; ribosomes

what all cells have