Unit 2 Biology Test: Cells and Structure

Cell Theory

The theory that all living things are composed of cells, cells are the most basic unit of life, and that all cells come from preexisting cells.

Cell Wall

(ALL plant SOME pro) Provides structural support, shape, and protection for the cell

Nucleus

(EUK plant & animal) Contains information in the form of deoxyribonucleic acid (DNA), which carries genetic instructions for the development, functioning, growth, and reproduction of our cells.

Nucleolus

(EUK) subspace within the nucleus that is concerned with producing and assembling the cell's ribosomes and ribosomal RNA (rRNA).

Chloroplast

(EUK Plant) Captures sunlight as energy in the form of glucose and then releases oxygen

Mitchondria

(EUK) The site for generating most of the chemical energy, ATP, needed to power the cell's biochemical reactions, using the process of cellular respiration.

Plasma Membrane

(ALL CELLS) It protects the cell from its environment and also regulates passage, communication, and cell shape.

Smooth ER

(EUK) involved with lipids and steroids (fats) synthesis and cell detoxification.

Rough ER

(EUK) protein synthesis (from ribosomes), processing, and folding of proteins (folding)

Ribosome

(ALL CELLS) considered as “protein factories” of the cell, as they can very rapidly make proteins as long as the mRNA is being delivered to it.

Golgi Apparatus

(EUK) functions to process and package proteins and lipids that are received from the ER, to be further processed and sorted for transport to their eventual destinations

Centriole(s)

(ANIMALS & SOME PLANTS) Facilitates cell division (mitosis) and the formation of cilia and flagella

Flagellum

Locomotion, allowing for movement within fluid environments

Cilia

Move fluids and debris

Lysosome

(ANIMALS) hydrolyzes macromolecules, recycles cellular waste, and plays a role in cellular signaling and energy metabolism.

Peroxisome

(EUK) The site of fatty acid breakdown and other compunds.

Cytoskeleton

(EUK) helps cells maintain their shape and internal organization, and it also provides mechanical support for cells to carry out their essential functions, like cell division and movement.

Cytoplasm

(ALL CELLS) provides a medium for processes to occur, supports the cell's shape, and facilitates the movement of materials throughout the cell

Endosome

(EUK) sort and direct internalized materials, either recycling them back to the cell surface or delivering them to lysosomes for degradation

Secretory Vesicle

(EUK & SOME PRO) moving molecules outside of the cell, through a process called exocytosis. They are crucial for healthy organ and tissue function.

Central Vacuole

(PLANT) big organelle that stores and releases molecules such as water

Endosymbiotic Theory

Mitochondria and chloroplasts are the result of years of evolution initiated by the endocytosis of aerobic bacteria and cyanobacteria, which instead of being digested, became symbiotic or helpful to the cell.

Evidence for Endosymbiotic Theory

1. Both mitochondria and chloroplasts have circular DNA, like prokaryotes

2. Mitochondria, chloroplasts, and prokaryotes divide using binary fission.

3. EUK cannot remake the organelles because their DNA is not stored in the nucleus.

Phagocytosis

A cellular process where cells engulf, ingest, and eliminate large particles like bacteria, microorganisms, and debris.

Mutualism

A type of symbiotic relationship in which all species benefit from the interaction

Cellular Respiration

Cellular respiration is the process by which cells derive energy from glucose. The chemical reaction for cellular respiration involves glucose and oxygen as inputs, and produces carbon dioxide, water, and energy (ATP) as outputs.

Photosynthesis

energy from sunlight is harvested and used to drive the synthesis of glucose from CO₂ and H₂O. By converting the energy of sunlight to a usable form of potential chemical energy, photosynthesis is the ultimate source of metabolic energy for all biological systems.