Biology — Chapter 5 Review

from both quiz & study guide

Unicellular

a single-celled organism that can function independently; examples include bacteria, protozoans, and some algae and fungi

Eukaryotic cells

possess a true nucleus and membrane-bound organelles; organisms like humans, animals, plants, fungi, and protists

Prokaryotic cells

includes organisms, such as bacteria, that lack a true nucleus and membrane-bound organelles

Cytoskeleton

a system of cytosolic fibers that maintains cell shape, organizes the cell's interior, and facilitates movement and division; it utilizes protein motors and tracks for cytoplasmic streaming and intracellular transport

Ribosome

cellular organelle that directs protein synthesis found in both prokaryotes and eukaryotes because it lacks a membrane; composed of protein and RNA, it aligns amino acids to create proteins

Chromatin

the genetic material of eukaryotic cells consisting of DNA and associated proteins, which is found in the nucleus

Isotonic

a solution that has a solute concentration equal to the cell's cytoplasm, which is the optimal condition for the cell to maintain homeostasis.

Cell theory

states that cells are the smallest unit of life, originate from preexisting cells, are the basic building blocks of all life, and perform life processes to maintain homeostasis; the modern version simplifies this, where cells are the structural and functional units of all living things and arise only from other preexisting cells

Diffusion

a type of passive transport where solute particles move from an area of higher concentration to lower concentration, resulting in the even distribution of particles throughout the solvent to create a uniform solution

Osmosis

the diffusion of water molecules through a semipermeable membrane; solvent particles move through a membrane from an area of lower solute concentration to an area of higher solute concentration

Spontaneous generation

the formation of a living thing from nonliving materials

Capsule

a slimy, protective coating found outside the cell wall and membrane of many bacteria; it contains water to prevent the cell from drying out

Passive transport

the type of movement of substances across a cell membrane without using chemical energy, which occurs because of the particles' natural motion, causing them to move from high to low concentration

Active transport

the energy-requiring movement of substances across a cell membrane from low to high concentration, using chemical energy

Plastid

organelles in plants and algae, either pigmented (chloroplasts) for converting light energy into chemical energy or colorless (leucoplasts) for storing starches, lipids, and proteins

Lysosomes

a cellular organelle that contains digestive enzymes; they are a type of vacuole found in human, animal, and animal-like cells (protozoans), and they digest food, kill bacteria and viruses, and recycle old cell parts

Robert Hooke

an Englishman who first used the term "cell" in 1665 to describe the box-like structures in cork viewed under a microscope, pioneering cytology; was also an accomplished artist, mathematician, architect, and astronomer, known for the drawings in his book Micrographia and for his work on gravitation that preceded Isaac Newton

van Leeuwenhoek

a Dutch scientist who discovered blood cells and studied sperm, bacteria, and larval cells using a microscope in 1682; whose work established that cells have a central part, and refuted the ideas of spontaneous generation and preformationism.

Matthias Schleiden & Theodor Schwann

a botanist and a zoologist who met for dinner in 1837 to discuss their shared idea that all plants and animals are made of cells

Robert Brown

a British botanist who, in 1831, named the central cell part that Leeuwenhoek and others had described, calling it the nucleus

Virchow

declared in 1858 that all cells come from preexisting cells

What is a bacterium's optimal temperature range?

usually about 30 °C, though those in the gut do best around normal body temperature (37 °C, 98.6 °F)

What causes a cell to die quickly?

conditions go beyond the limit of tolerance

Which type of cells contain organelles?

both prokaryotic and eukaryotic cells, but only eukaryotic cells have them membrane-surrounded

Where does photosynthesis happen?

in a cell's chloroplast, specifically in the grana, or stacks of thylakoids, within the stroma

In which direction does a semipermeable membrane allow particles to pass?

it allows solvent particles (water) to move from an area of lower solute concentration to an area of higher solute concentration (osmosis)

Where is the nucleus found?

in eukaryotic cells, controlling cell actions and containing its genetic material

What causes the roughness of the endoplasmic reticulum?

being studded with ribosomes

What is cellular research?

studying cells and their environment to gain understanding and develop treatments that save and improve lives

Describe a cell colony.

a group of individual organisms of the same species that live closely together but whose cells can break away and function on their own

Golgi apparatus functions

receives substances from the ER, packages them into vesicles, and sends vesicles within or outside the cell

Know the structures of an animal cell and a plant cell

plant cells have unique structures like a cell wall, central vacuole, and plastids, like chloroplasts and leucoplasts, while animal cells typically contain lysosomes and a centrosome

Know the differences between hypertonic, hypotonic, and isotonic solutions

isotonic means equal solute concentration to cytoplasm, hypertonic means greater concentration, and hypotonic means lesser concentration

Know the feedback mechanisms within a cell

positive feedback where a substance speeds up a process, and negative feedback where a product inhibits the process itself

Cytology

the study of cells and their functions/properties

Zoology

the study of animals and their functions/properties

Briefly describe the three ways cells are organized

unicellular, multicellular, colony

Multicellular

an organism that contains more than one cell

Colony

a group of two or more of the same types of cells working and associating together

Cell association to organ systems

organisms -> tissues -> organs -> organ systems

Dynamic equilibrium

balanced motion and changes within a system

What are the two main types of cell transport?

Passive, Active

Endocytosis

formation of a sack around a molecule by the cell membrane that pinches off to become a vesicle