Biology 1033 Exam 2 Dr. Hasek Questions and Answers 100% Pass

Biology 1033 Exam 2 Dr. Hasek Questions and Answers 100% Pass What is the name for integral proteins that span only part of the cell membrane? - A) Peripheral proteins - B) Transmembrane proteins - C) Surface proteins - D) Cytoplasmic proteins Explanation: Transmembrane proteins span the entire membrane, embedding themselves within it and often facilitating communication and transport between the inside and outside of the cell. Which statement accurately describes the fluid nature of cell membranes? - A) Phospholipids and some proteins can move laterally within the bilayer. - B) Membrane proteins are immobile. - C) Molecules frequently flip across the bilayer. - D) Membranes are rigid structures. 2 Explanation: The fluid mosaic model describes the cell membrane as a dynamic and flexible structure where phospholipids and some proteins can move sideways within the layer, contributing to its fluidity. How is a membrane that allows certain substances to pass more easily than others described? - A) Permeable - B) Impermeable - C) Selectively permeable - D) Non-permeable Explanation: Selectively permeable membranes regulate the movement of substances, allowing some to pass through while blocking others, thus maintaining homeostasis. Which process involves the movement of molecules from a high concentration to a low concentration without using energy? - A) Active transport 3 - B) Passive transport - C) Bulk transport - D) Osmosis Explanation: Passive transport does not require energy and occurs when molecules move along their concentration gradient from a region of higher concentration to lower concentration. What transport method moves substances across the cell membrane using energy against a concentration gradient? - A) Passive transport - B) Diffusion