Cells - CTR - Week 1

What is the difference between prokaryotic and eukaryotic cells regarding their genetic material?

Eukaryotic chromosomes are found inside a membrane-bound nucleus; prokaryotes have DNA strands in the cytoplasm.

What is the primary function of the plasma membrane?

Controlling the movement of water-soluble substances into and out of the cell.

Which organelles are involved in protein synthesis?

Ribosomes and the rough endoplasmic reticulum.

What is the role of the mitochondria?

ATP production through aerobic respiration.

What is a lysosome's main function?

To digest and dispose of unwanted materials within and outside the cell.

What structure surrounds eukaryotic cells?

The plasma membrane.

Describe the cytoskeleton's function.

The cytoskeleton helps maintain cell shape, anchors organelles, aids in cell division, and enables cell movement.

What are the main components of the endomembrane system?

ER, Golgi apparatus, nuclear envelope, lysosomes, vacuoles, and vesicles.

How does DNA replication occur?

DNA helices unwind, and each strand serves as a template for building new complementary strands.

What are the three main types of RNA involved in protein synthesis?

Messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA).

What is the primary structure of DNA?

A double-stranded helical molecule composed of nucleotides.

Define transcription in the context of protein synthesis.

The process of transferring DNA gene base sequence to a complementary base sequence of mRNA.

What are ribosomes primarily responsible for?

The synthesis of proteins.

What does the term 'chromatin' refer to?

The complex of DNA and proteins that forms chromosomes in the cell nucleus.

What happens during the S phase of the cell cycle?

DNA is synthesized and replicated.

What is the role of histones in DNA structure?

They package and regulate DNA.

What is the difference between rough and smooth endoplasmic reticulum?

Rough ER has ribosomes and synthesizes proteins; smooth ER lacks ribosomes and is involved in lipid metabolism.

What do peroxisomes do?

They degrade harmful substances, particularly oxygen free radicals.

How are proteins processed after synthesis at the rough ER?

Proteins may undergo folding and modification and are packaged into vesicles for transport.

What is the function of the Golgi apparatus?

To modify, concentrate, and package proteins and lipids made in the ER.

How are mature mRNA molecules formed?

Pre-mRNA undergoes processing before being transported out of the nucleus.

What are the components of the cytoplasm?

Cytosol, organelles, inclusions, and the cytoskeleton.

What initiates the process of translation?

The binding of mRNA to a ribosome.

What are centrioles and their role in cells?

Centrioles are structures that help organize microtubules during cell division.

What do aquaporins do?

They facilitate the transport of water across the plasma membrane.

What is the result of a mutation in a gene?

It can lead to a change in the amino acid sequence of a protein.

What is produced during the process of glycolysis?

ATP and pyruvate from glucose.

Describe the structure of RNA.

Single-stranded and composed of ribonucleotides with bases adenine, guanine, cytosine, and uracil.

Define the term 'extracellular matrix'.

A network of proteins and carbohydrates that provide structural support to cells.

How does the concentration gradient influence cellular transport?

It drives the movement of substances from areas of high concentration to areas of low concentration.

What is the ultimate goal of transcription?

To create an mRNA strand that carries the genetic information for protein synthesis.

What is the monomer of proteins?

Amino acids.

Describe the main function of cilia.

Cilia beat back and forth to move entire cells or substances across cell surfaces.

What types of molecules can easily pass through the phospholipid bilayer?

Small nonpolar molecules can pass through easily.

How does the structure of the plasma membrane relate to its function?

Its fluid, flexible nature allows selective permeability and communication with the environment.

What process allows cells to produce energy in the absence of oxygen?

Anaerobic respiration.

What determines the genetic code of an organism?

The sequence of nucleotides in DNA.

What do vacuoles primarily store?

Materials like water, nutrients, and waste products.

What is the term for programmed cell death?

Apoptosis.

What is the significance of the nucleolus within the nucleus?

It synthesizes ribosomal RNA and assembles ribosome subunits.

What role do chaperone proteins play in cells?

They assist in the proper folding of proteins after synthesis.

What is the purpose of cellular respiration?

To convert biochemical energy from nutrients into ATP.

What are the components of a nucleotide?

A nitrogenous base, a pentose sugar, and a phosphate group.

What happens during prophase of mitosis?

Chromosomes condense and the nuclear envelope breaks down.

What are the roles of enzymes in cellular processes?

They speed up chemical reactions by lowering activation energy.

What is the main purpose of mitosis?

To ensure the equal distribution of replicated chromosomes into daughter cells.

In what part of the cell does translation take place?

In the cytoplasm at the ribosome.

What is an amino acid composed of?

An amino group, a carboxyl group, a hydrogen atom, and an R group.

What is the first step in cellular respiration?

Glycolysis.

Which organelle is known as the powerhouse of the cell?

Mitochondria.

What is the primary function of transfer RNA (tRNA)?

To bring amino acids to ribosomes during protein synthesis.

What does the term 'autolysis' mean?

Self-digestion of a cell due to lysosomal rupture.

What is the difference between diploid and haploid cells?

Diploid cells have two sets of chromosomes, while haploid cells have one set.

Describe the role of the signal recognition particle (SRP).

To guide the mRNA-ribosome complex to the rough endoplasmic reticulum.

What is the post-translational modification of proteins?

Chemical modifications after protein synthesis that affect protein function.

What are the two phases of the cell cycle?

Interphase and mitotic phase.

What are the primary products of the light-dependent reactions of photosynthesis?

ATP and NADPH.

What is the significance of the rough endoplasmic reticulum?

It plays a key role in protein synthesis and processing.

What distinguishes cancer cells from normal cells?

Cancer cells exhibit uncontrolled division and abnormal growth.

What is the function of the nuclear envelope?

To separate the contents of the nucleus from the cytoplasm.

What are some characteristics of eukaryotic cells?

They have a complex structure with membrane-bound organelles and a nucleus.

Which component of the cytoskeleton is involved in maintaining cell shape?

Microtubules.

Define 'gene expression'.

The process by which a gene's information is used to synthesize functional gene products, typically proteins.

What is the fundamental building block of nucleic acids?

Nucleotides.

Explain the role of phospholipids in the plasma membrane.

They form the bilayer that creates a barrier to protect the cell.

What does 'selective permeability' refer to in cellular membranes?

The ability of a membrane to allow certain substances to pass while restricting others.