Question 1

Exocytosis involves

Accepted Answer

A)  the transport of cellular products to the external environment in membrane vesicles. 
B)  the transport of extracellular products into the cell. 
C)  the formation of clathrin coated pit. 
D)  binding of a vesicle to a specific protein receptor molecule. 
E)  the fusion of a vesicle with a lysosome to activate the proteins. 
A)  the transport of cellular products to the external environment in membrane vesicles. 
B)  the transport of extracellular products into the cell. 
C)  the formation of clathrin coated pit. 
D)  binding of a vesicle to a specific protein receptor molecule. 
E)  the fusion of a vesicle with a lysosome to activate the proteins.

Question 2

The diffusive force for a charged substance depends on its concentration gradient and the electrical potential across the membrane. Which statement about the net movement of the charged substance across the membrane of a cell is CORRECT?

Accepted Answer

A)  The substance can only move from where it is in higher concentration to where it is in lower concentration. 
B)  Net movement of the substance will continue along the charge gradient when electrochemical equilibrium is reached. 
C)  The substance will move against its electrical gradient if the opposing concentration gradient is small enough. 
D)  The substance can move from where it is in higher concentration to where it is in lower concentration if the charge gradient exceeds the opposing concentration gradient. 
E)  The substance can move along the electrochemical gradient only when the charge difference is very large. 
A)  The substance can only move from where it is in higher concentration to where it is in lower concentration. 
B)  Net movement of the substance will continue along the charge gradient when electrochemical equilibrium is reached. 
C)  The substance will move against its electrical gradient if the opposing concentration gradient is small enough. 
D)  The substance can move from where it is in higher concentration to where it is in lower concentration if the charge gradient exceeds the opposing concentration gradient. 
E)  The substance can move along the electrochemical gradient only when the charge difference is very large.

Question 3

Movement through certain ion channels

Accepted Answer

A)  is influenced by the presence of specific signal molecules. 
B)  is slow compared to transport by protein carriers. 
C)  requires the presence of ATP. 
D)  is always independent of the electrical potential difference across the membrane. 
E)  is non-selective for particular solutes. 
A)  is influenced by the presence of specific signal molecules. 
B)  is slow compared to transport by protein carriers. 
C)  requires the presence of ATP. 
D)  is always independent of the electrical potential difference across the membrane. 
E)  is non-selective for particular solutes.

Question 4

In animal cells, the action of the Na+-K+ translocating ATPase results in a net export of

Accepted Answer

A)  Na+, with no associated net change in membrane potential. 
B)  K+, with no associated net change in membrane potential. 
C)  Depending on the cells' homeostatic requirements, it can be either Na+ or K+. 
D)  Na+, and an associated positive charge. 
E)  K+, and an associated positive charge. 
A)  Na+, with no associated net change in membrane potential. 
B)  K+, with no associated net change in membrane potential. 
C)  Depending on the cells' homeostatic requirements, it can be either Na+ or K+. 
D)  Na+, and an associated positive charge. 
E)  K+, and an associated positive charge.

Question 5

Carrier proteins do NOT

Accepted Answer

A)  get inhibited by similar molecules which compete for the binding site. 
B)  act like a pore in the membrane to allow ions to flow rapidly along the electrochemical gradient. 
C)  tend to transport molecules more slowly that transport by channels. 
D)  require the hydrolysis of metabolic energy for transport. 
E)  bind a solute to be transported in a hydrophilic pocket causing a conformational change in the protein. 
A)  get inhibited by similar molecules which compete for the binding site. 
B)  act like a pore in the membrane to allow ions to flow rapidly along the electrochemical gradient. 
C)  tend to transport molecules more slowly that transport by channels. 
D)  require the hydrolysis of metabolic energy for transport. 
E)  bind a solute to be transported in a hydrophilic pocket causing a conformational change in the protein.

Exam 5: Movement Across Membranes

Exocytosis involves

The diffusive force for a charged substance depends on its concentration gradient and the electrical potential across the membrane. Which statement about the net movement of the charged substance across the membrane of a cell is CORRECT?

Movement through certain ion channels

In animal cells, the action of the Na+-K+ translocating ATPase results in a net export of

Carrier proteins do NOT

Nature of Molecules

Biomolecules

The Chemistry of Life

Functioning Cells

Harvesting Energy

Cells, Tissues and Signals

Cell Division

Inheritance

Genes, Chromosomes and Dna

The Genetic Code

Gene Expression

Genomes, Mutation and Cancer

Viruses

Genetic Engineering and Biotechnology

Reproduction, Growth and Development of Flowering Plants

Structure of Plants

Plant Nutrition, Transport and Adaptation to Stress

Plant Hormones and Growth Responses

Animal Reproduction

Animal Development

Homeostasis: Water, Solutes and Excretion

Gas Exchange in Animals

Circulation

Metabolism, Temperature Regulation and Environmental Stress

Animal and Human Nutrition

Innate Defences and the Immune System

Hormonal Control in Animals

Nervous Systems

Animal Movement

Animal Behaviour

Evolving Life

Evolving Earth

Mechanisms of Evolution

Bacteria

The Protists

Plants

Fungi

Simple Animals: Sponges to Flatworms

Annelids, Molluscs, Nematodes and Arthropods

Echinoderms and Chordates

Australian Biota

Population Ecology

Living in Communities

Ecosystems

Human Impacts

Filters

In animal cells, the action of the Na⁺-K⁺ translocating ATPase results in a net export of