Unit 3: The Cell

A set of practice flashcards covering cell characteristics, types, the endosymbiotic theory, and the functions of various organelles based on the Unit 3 lecture notes.

What are the seven characteristics of life described in the material?

01 Growth and development, 02 Organization, 03 Homeostasis (regulating internal environment), 04 Metabolism (transforming/transferring energy), 05 Reproduction/transferring biological information, 06 Irritability (response to the environment), and 07 Evolution.

What is the defined size range for most cells?

They range in size from $1$ to $100\,μm$, although some reach nearly $1\,mm$.

What is the primary distinction between prokaryotic and eukaryotic cells?

Prokaryotic cells do not have a nucleus surrounding the ADN, whereas eukaryotic cells possess a nucleus and organelles.

What does the endosymbiotic theory proposed by Lynn Margulis in 1967 suggest?

It proposes that the eukaryotic cell originated when an Archaea without a capsule engulfed a respiratory bacteria without digesting it, eventually forming the mitochondria.

What four pieces of evidence support the endosymbiotic theory?

1. Double membrane, 2. Independent circular ADN, 3. Independent ribosomes, and 4. Genetic relationship with alpha proteobacterias.

What is the function of the nucleolus within the cell nucleus?

Its function is to synthesize ARNs.

What are the functions of the cytoplasm in conjunction with the cytoskeleton?

It provides support for the cell and allows for the transport of substances, acting as the hydrosaline medium where organelles are found.

What is the role of ribosomes and where are they located?

Ribosomes are formed by protein and ARN, located freely in the cytoplasm or on the rough endoplasmic reticulum; they synthesize proteins using ARNm from the nucleus as a guide.

How do the functions of the Rough and Smooth Endoplasmic Reticulum (ER) differ?

The Rough ER is involved in the synthesis and transport of proteins, while the Smooth ER is involved in the synthesis and transport of lipids.

What are the four main functions of the Golgi apparatus?

1. Separates proteins and lipids from the RE by destination, 2. Modifies some proteins by adding polysaccharides or lipids, 3. Packages materials into vesicles for transport, and 4. Assembles lysosomes.

What is the purpose of vacuoles in a cell?

They are storage organelles for water, nutrients, and ions, and they help maintain the osmotic pressure of the cell.

Where do vesicles originate and what is their role?

Vesicles transport substances between the membrane and organelles; they can originate from the RE, Golgi apparatus, or the cell membrane (endosomas).

What is the difference between lysosomes and peroxisomes?

Lysosomes are specialized vesicles with digestive enzymes used to degrade nutrients or invaders, while peroxisomes contain enzymes that act against reactive oxygen species to protect the cell from oxidation.

What is the function of the mitochondria?

To generate metabolic energy ($ATP$) through cellular respiration.

What is the primary function of chloroplasts?

Photosynthesis, which uses solar energy to transform it into chemical energy stored in the bonds of glucose molecules.

What is the composition of the cell membrane?

It is composed of a phospholipid bilayer, proteins, and carbohydrates (oligosacáridos).

What are the three types of proteins that form the cytoskeleton?

Microfilamentos, microtóbulos, and filamentos intermedios.

What are the functional differences between cilia and flagella?

Both generate motility to locate nutrients or respond to stimuli, but cilia are short and numerous, while flagella are long and few.

According to the diagrams, which structures are unique to plant cells compared to animal cells?

Cell wall, chloroplasts, and a central vacuole.