Biomolecules and Cellular Organization: Key Concepts for Biology

What are the four classes of biomolecules?

Carbohydrates, Lipids, Proteins, Nucleic Acids

What defines an organic compound?

A compound that contains carbon.

What is a monomer?

The simplest form of each biomolecule.

What elements make up carbohydrates?

Carbon, Hydrogen, and Oxygen (CHO)

What are the functions of carbohydrates?

Provide energy and are stored as glycogen for later use.

What is the monomer of carbohydrates?

Monosaccharides

What elements make up lipids?

Carbon, Hydrogen, and Oxygen (C, H, O) with a high ratio of hydrogen to oxygen.

What are examples of lipids?

Steroids, Triglycerides, and Phospholipids

What is the primary function of lipids?

Energy storage and some cell signaling.

What are the elements that compose nucleic acids?

Carbon, Hydrogen, Oxygen, Nitrogen, and Phosphorus (C, H, O, N, P)

What is the function of nucleic acids?

Store genetic information and assist with protein synthesis.

What is the monomer of nucleic acids?

Nucleotides

What are the three components of a nucleotide?

Nitrogenous base, Sugar (monosaccharide), and one or more phosphate groups.

What is the monomer of proteins?

Amino acids

How many unique amino acids are there?

20 unique amino acids.

What determines the properties of a protein?

The combination and properties of the R groups in amino acids.

What are the four levels of protein structure?

Primary, Secondary, Tertiary, and Quaternary structures.

What is the primary structure of a protein?

The amino acid sequence.

What is the secondary structure of a protein?

Local coils or folds shaped by hydrogen bonds between nearby amino acids.

What is the tertiary structure of a protein?

Further folding and bending into globular and fibrous shapes.

What is the quaternary structure of a protein?

Association of two or more separate protein chains.

What is an enzyme?

A protein that acts as a biological catalyst, promoting rapid reaction rates by lowering activation energy.

What factors affect enzyme activity?

Temperature and pH.

What is the function of the plasma membrane?

To protect the cell and regulate what enters and exits.

What is cell theory?

The theory that all living things are composed of cells, and all cells arise from pre-existing cells.

What is cytology?

The study of structure and function of cells.

What are the four main points of cell theory?

1. All living things are composed of at least one cell. 2. The cell is the simplest structural and functional unit of life. 3. An organism's structure and functions are due to the activities of its cells. 4. Cells come only from preexisting cells.

What are the three main parts of eukaryotic cells?

Plasma membrane, cytoplasm, and nucleus.

What is the structure of the plasma membrane?

A double layer of phospholipid molecules with hydrophilic heads facing the watery environment and hydrophobic fatty-acid tails inside.

What are the functions of the plasma membrane?

Forms cell boundary, protects the cell, regulates transport, links to other cells, and serves as markers for recognition.

What is selective permeability in plasma membranes?

The ability to regulate what enters and exits the cell.

What is active transport?

Movement of substances against their concentration gradient that requires energy.

What is passive transport?

Movement of substances down their concentration gradient without the need for energy.

What are microvilli?

Out-folded projections that increase surface area, primarily found on cells that perform absorption.

What are cilia?

Short, hair-like projections that move fluids along a cell surface.

What is the function of ribosomes?

To build proteins; they are the site of translation.

What is the difference between rough ER and smooth ER?

Rough ER has ribosomes attached and synthesizes proteins, while smooth ER has no ribosomes and synthesizes carbohydrates and lipids.

What is the function of the Golgi apparatus?

To synthesize carbohydrates and modify, sort, and package proteins for transport.

What do lysosomes do?

Digest cellular materials, pathogens, and damaged organelles.

What are mitochondria known as?

The powerhouses of the cell, generating ATP.

What is the nucleus's role in the cell?

It is the control center that contains DNA, which codes for protein structures and functions.

What are the steps of protein synthesis?

1. Transcription of DNA to RNA in the nucleus. 2. Translation of RNA to protein at the ribosome. 3. Modification and packaging in the Golgi apparatus.

What is cellular diversity?

The presence of nearly 100 trillion cells of about 200 different types in an adult, allowing for complex tissue and organ organization.

What is the process that uses DNA to build RNA called?

Transcription.

What is the process that uses RNA to build protein called?

Translation.

What organelles would a cell that produces and secretes many proteins likely have in higher abundance?

Ribosomes, rough ER, and Golgi apparatus.