GENERAL BIOLOGY (1ST QUARTER)

Cell

The Basic Unit of Life

Hans and Zacharias Janssen

Both inventors are knownn for inventing the compound optical microscope. This invention contributed to the cell theory by making it easier and more practical while observing cells. They also discovered the single cell animal.

Robert Brown

A British botanist who first discovered the nucleus in plant cells and its role helped to put together the cell theory, which states that all living organisms are composed of cells and cells come from pre-existing cells his discovery helped to confirm the second half the cell theory.

Theodor Schwanи

A biologist and physiologist who concluded that all animal tissues were made of cells as well. He blended both statements into one theory which said

1.) All living organisms consist of one or more cells and

2.) The cell is the basic unit of structure for all living organisms.

Robert Koch

He was a German doctor who developed staining techniques that improved visibility of bacteria under the microscope

Max Knoll and Ernst Ruska

Both of them built the first electron microscope that could magnify at 400x. These microscopes allowed scientists to study pieces and processes inside cells that they could not see before. Their invention also made overcome the barrier to higher resolution due to the limitation of visible light.

Robert Hooke

A British scientist who published Micrographia wherein it is illustrated the smallest complete parts of an organism. When scientist Robert Hookе looked at a thin slice of cork under the microscope, he saw a honeycomb structure made up of small compartments. He is the one who named these organisms or compartments, cells.

Antonie Van Leeuwenhock

A Dutch microscopist who was the first to see living cells under a microscope. On the same year, he significantly improved the quality of microscopе lenses to the point that he could see the single-celled organisms that lived in a drop of pond water He called these organisms "animalcules", which means "miniature animals".

Matthias Schleiden

A German Botanist, together with bás cofounder, Schwann, proposed the first foundational belief about cells, that all plant tissues are composed of cells. On the name year, Schleiden concluded that all plant tissues are composed of cells and that an embryonic plant arose from a single cell. He declared that the cell is the basic building block of all plant matter.

Rudolf Virchow

A German pathologist who concluded that Omis cellulae cellula which translates roughly from Latin to "calls only arise from other cells".

Ernest Everett Just

He was a pioneering African-American biologist, academic and science writer studied the functions and structure of the cell.

Prokaryotic Cells

are the simplest organism

Cytoplasm

In bacteria, the ________ is surrounded by a plasma membrane

Cell wall

The ______ maintains the shape of the cell

Peptidoglycan

This cell wall is composed of ______ , which consists of a carbohydrate matrix (polymers of sugars) that is cross-linked by short polypeptide units.

Nucleoid

In bacteria, the DNA is located in a single circular, coiled chromosome that resides in a region of the cell called the ______

Ribosomes

The many proteins specified by bacterial DNA are synthesized on tiny structures called

Flagella

(singular, flagellum) are long, threadlike structures protruding from the surface of a cell that are used in locomotion

Eukaryotic Cells

are far more complex than prokaryotic cell

Compartmentalization

The hallmark of the eukaryotic cell is

Endomembrane system

This is achieved through a combination of an extensive _______ that weaves through the cell interior and by numerous organelles

Nucleus

The largest and most easily seen organelle within a eukaryotic cell is the _____ (Latin, “kernel” or “nut”), first described by the Scottish botanist Robert Brown in 1831

Nuclei

Are roughly spherical in shape, and in animal cells, they are typically located in the central region of the cell

Nucleolus

Many nuclei exhibit a dark-staining zone called the _____, which is a region where intensive synthesis of ribosomal RNA is taking place

Chromatin

In eukaryotes, the DNA is divided into multiple linear chromosomes, which are organized with proteins into a complex structure called

Nucleoli

These ribosomal assembly areas are easily visible within the nucleus as one or more dark- staining regions called ______ (singular, nucleolus)

Ribosomes

are among the most complex molecular assemblies found in cells.

Ribosomal RNA (rRNA)

Each ribosome is composed of two subunits (large and small subunit), each of which is composed of a combination of RNA called ________

“Universal organelles”

Ribosomes can be thought of as _______ because they are found in all cell types from all three domains of life

Endoplasmic reticulum (ER)

The largest of the internal membranes is called the

rough endoplasmic reticulum (RER)

The________ gets its name from its pebbly surface appearance.

proteins synthesized

The __________ on the surface of the RER are destined to be exported from the cell, sent to lysosomes or vacuoles (described later in this section), or embedded in the plasma membrane

smooth ER (SER)

Regions of the ER with relatively few bound ribosomes are referred to as

Golgi body, or Golgi apparatus

Flattened stacks of membranes form a complex called the

Cisternae

The individual stacks of membrane are called ______ (Latin, “collecting vessels”), and they vary in number within the Golgi body

lysosomes

Membrane-bounded digestive vesicles, called ________, are also components of the endomembrane system

Peroxisome

contains enzymes involved in the oxidation of fatty acids

vacuoles

Plant cells have specialized membrane-bounded structures called

Vacuole

actually means blank space, referring to its appearance in the light microscope

tonoplast

The membrane surrounding this vacuole is called the ______ because it contains channels for water that are used to help the cell maintain its tonicity, or osmotic balance

Mitochondria

(singular, mitochondrion) are typically tubular or sausage-shaped organelles about the size of bacteria that are found in all types of eukaryotic cell

Cristae

inner folded membrane with numerous contiguous layers called ______ (singular, crista)

matrix

a ______, lying inside the inner membrane

intermembrane space

lying between the two mitochondrial membrane

Chloroplasts

contain the photosynthetic pigment chlorophyll that gives most plants their green color

grana

chloroplasts have closed compartments of stacked membranes called ____ (singular, granum), which lie inside the inner membrane

thylakoids

each granum may contain from a few to several dozen disk-shaped structures called

stroma

Surrounding the thylakoid is a fluid matrix called the

plastids

. chloroplasts, leucoplasts, and amyloplasts—are collectively called

Actin filaments

are long fibers about 7 nm in diameter. Each filament is composed of two protein chains loosely twined together like two strands of pearls (actin)

Microtubules

the largest of the cytoskeletal elements, are hollow tubes about 25 nm in diameter, each composed of a ring of 13 protein protofilaments

Intermediate filaments

are the most durable element of the cytoskeleton in animal cells is a system of tough, fibrous protein molecules twined together in an overlapping arrangement

Centrioles

are barrel-shaped organelles found in the cells of animals and most protists

centrosome

The region surrounding the pair in almost all animal cells is referred to as a

flagellum

As pairs of microtubules move past each other using arms composed of the motor protein dynein, the eukaryotic _____undulates, or waves up and down, rather than rotates.

Cilia

are short cellular projections that are often organized in rows

primary walls

In plants, _______ are laid down when the cell is still growin

middle lamella

Between the walls of adjacent cells a sticky substance, called the ______, glues the cells together.

secondary walls

Some plant cells produce strong _______, which are deposited inside the primary walls of fully expanded cells.

1. Gathering and Using Energy

2. Maintaining Internal Balance

3. Responding, Adapting, and Evolving

4. Reproducing and Continuing Life

5. Living and Interacting

Characteristics shared by living systems

Cellular Respiration

is a process by which energy is released by the breakdown of food substances.

Energy

➢ _______ is the ability of organisms to do work that allows them to move.

➢ _______ is produced when complex organic matter (biomolecules) are broken down into simple substances.

Metabolism

is the sum of all chemical processes and energy changes happening inside the body of an organism.

Nutrition

is the process by which organisms acquire food in order to survive, grow, and reproduce.

Excretion

is the process of removing waste.

Homeostasis

is the maintenance of the body’s internal environment.

Locomotion or Motility

is the movement from one place to another.

Sensitivity or Irritability

is the ability of an organism to respond appropriately to a stimulus.

Tropism or response

is the reaction of an organism to stimuli.

Evolution

refers to the changes in the characteristics of a group of organisms (species) over time.

Development

refers to the defined stages in the life cycle of a living thing from fertilization to death.

Intussusception

is a process where living things exhibit growth from within the cells.

Growth

is an increase in size and volume by converting food to become a part of body cells.

Accretion

which is a growth by external addition of substances for nonliving things

Reproduction

is a process by which genetic information is passed on from one generation to another as organisms produce offspring.

DNA

is used as a physical carrier of the transferred genetic information through sexual reproduction.

Sexual Reproduction

is the union of sex cells from two parents produce a unique individual of their kind

Asexual Reproduction

occurs when an organism makes copies of itself.

Living things

exhibit a high degree of organization from molecular to cellular level.

Abiogenesis

is the idea that life originates from nonliving matter

Biogenesis

is the belief that life originates from preexisting life.

Redi’s Experiment (Francesco Redi)

He concluded that life arose from living matter and not from spontaneous generation.

Needham’s Experiment (John Needham)

Needham concluded that life in the broth was caused by spontaneous generation, however, he did not heat it long enough to kill all the microbe in the broth.

Spallanzani’s Experiment (Lazzaro Spallanzani)

air from his sealed flasks, which they believed was needed for spontaneous generation to occur.

Pasteur’s Experiment (Louis Pasteur)

evidence suggests that new organisms arise only when they are produced by existing organisms.

Creationism

is believed that life forms and everything in the universe were created through a supernatural power rather than naturalistic means.

Spontaneous Origin

➢ Life evolved from inanimate matter.

➢ The famous Miller-Urey experiment suggested that lightning may have helped trigger the creation of the key building blocks of life.

Panspermia

➢ Proposes that a meteor or cosmic dust may have carried to Earth significant amounts of organic molecules, which started the evolution.

Cellular Membrane

Plasma membrane, outermost component that separates (inside) intracellular components from (outside) extracellular components Supports cell content, acts as a selective barrier, and plays roles in communication between cells Selectively permeable

Sandwich model (Davson-Danielle 1950s):

phospholipid bilayer is sandwiched between two layers of globular proteins.

Fluid Mosaic model (S.J. Singer and G. Nicolsor 1972):

globular proteins are inserted into lipid bilayer. A mosaic of protein floats in or on the fluid bilayer like boats on a pond.

Integral proteins

Peripheral proteins

Phospholipids

Cell membrane is composed of

two fatty acid chains

This contains _________ linked to two fo three carbon atoms of glycerol molecules.

Phospholipids

a amphipathic molecules

Polar Head-

is composed of glycerol and phosphate group (hyrophilic)

Non-polar Tail-

fatty acid chain (hydrophobic)

Transmembrane protein

Variety of functions, including transport and communication across the membrane

- Interior protein network

intracellular proteins that reinforce the membrane's shape

- Cell surface marker

glycoproteins and glycolipids on the surface that act as cell identity marke

selective permeability

A cell must exchange molecules and ions with its surroundings, a process controlled by the _______ of the plasma membrane.